We all know it is important to not only set goals, but also to talk about why some reach their goals and why others don't.

From what I've seen, people set goals but often don't realize the amount of work it'll take to reach those goals. Many times, the goal you want to reach will force many changes in your life, and many of those changes will be big changes.

Lifestyle changes that not only affect you, but those around you. For example, let's say you're trying to stop smoking. How hard would it be if on your work breaks everyone you sit and chat with is smoking?

What if you're trying to lose weight, but your spouse is not, and they still prefer to eat chips, cakes and cookies everyday before and after dinner? Are you on your feet or on the go all day? That type of hectic schedule can undermine your ability to eat small, balanced meals throughout the day.

It's these and other (not so small) details that can really determine if a person will reach their goals. And while these and other roadblocks can slow a person down, they can be overcome.

Subtle sabotage

Not everyone will see your goal or vision in the beginning. Some will even tell you that your goal isn't very realistic or feasible. Please understand that not everyone who says this will have your best interests at heart. I mean, hey, let's keep it real.

There are those close to you who may not want you to succeed. Why? Because your success will make them look bad. Your success will force them to look at their own lives and realize they didn't live up to their potential.

Think about it: it's so much easier to blame the world for your shortcomings if you're surrounded by a bunch of underachievers. It's easy to say life is against you if others around you have half-heartedly tried and failed.

But here you come. Here you are with all this ambition and goals. You're messing everything up with all this positivity and ambition. People will never admit they feel this way, but trust me when I say it exists.

There are also those who simply don't believe it can happen. They think the goals or dreams you have are reserved for other folks. Who are these "other folks"? These are the people who don't look like them, talk like them or live where they live.

Rapper Jay-Z is a perfect example of this. Jay-Z grew up in the projects in Brooklyn, and he sold drugs. When he started rapping, there were those around him that said he wouldn't succeed, and he wouldn't amount to anything. Partly because of where he grew up.

If you think about it, they were right: How many people from his neighborhood became world famous? Here's the kicker: they were looking at things from their own limited perspective.

They were confined mentally to their own limitations and doubts, and had no problem passing their views on to the next person. And when the record labels slammed doors in his face, they felt validated in what they were telling him.

So my point is to stay focused on your goals. Jay-Z did just that, and the rest is history. No one can see things exactly from your perspective, and it's also important to remember these goals are yours.

The man in the mirror

Aside from others sabotaging your goals, guess who else can sabotage your goals? The person who has the biggest influence on you can be the deciding factor between success and failure. Know who that person is? It's you. The man in the mirror.

You have the final say in what happens and how successful you are in your journey. If you really want to do something, no one can stop you.

Think back to when you were a kid and your mom told you not to do something. What happened? You did it anyway! Now on the flip side: do you know anyone who had a lot of talent, and everybody said they had a great gift, but they ended up wasting it or throwing it away?

In both cases things went the way they did because their minds were made up. They decided they were going to do what they wanted to do, never mind what others said. What it all comes down to is you and your belief in yourself. It's crucial you believe in yourself and know beyond a shadow of a doubt that you will reach your goal.

Now this brings me to another reason people fail. Many people will become discouraged and give up just when things start to get tough, or if things aren't going as smoothly as planned.

Comfort zones

Many of us are afraid to get out of our comfort zones. We don't want to be put in a situation that forces us to rely on faith, or to work even harder than we'd like.

When Tyler Perry first started out, he was living in his car in 1992. Only 30 people showed up for his first play. Talk about being out of your comfort zone. Talk about wanting to give up.

I can only imagine how many people told him to give up, or all the voices in his head that suggested he quit. But he did not let that hurt and discomfort stop him from making his dreams come true.

Are you trying to lose weight? Trying to resist that intense craving for soda and sweets is taking you out of your comfort zone.

Are you training for your first 10K? The discomfort you feel at Mile 4 that makes you want to stop now is your body getting out of its comfort zone.

It's pretty simple actually: Whatever you're trying to accomplish, in order to take things to the next level, you'll experience levels of discomfort. You'll have to do something you've never done before, and it'll be a shock to the system, but eventually you'll get used to it.

Ever get in a pool and it's cold when you first get in? You start out by dipping your big toe in the water then jump back. Maybe you'll sit on the side and let your legs dangle in the water for a couple minutes? Then, if you haven't been splashed, you might slowly get in the water.

Now this whole episode could take two minutes or 20, depending on the person. Or, they could just give up and call it a day.

This is a good example of a person out of their comfort zone and trying to adjust to the situation. What's going on here is a person is getting comfortable with the cool water. They're not used to it and trying to deal.

This is just one example of a comfort zone we all can relate to. This example is physical. Others are more mental. If you tell yourself "this feeling is only temporary," you can withstand the discomfort long enough for your body to adapt. Just like the water, it may take a minute or two, but in time your body will adjust.

So my point here is when people try something new, they get upset or frazzled because they are put in a situation they aren't used to. When going for a new goal, I can guarantee you that you will be taken out of your comfort zone. What is your specific comfort zone? I don't know, and there's a chance you won't know it either, until you reach your limit.

When riding my bike, I'm comfortable for about three hours. When I get over three hours on the bike I start to suffer. That's where my mental toughness starts to come in, and I push myself to keep going. The same principle applies to you, when you're out of your comfort zone.

This is where your mental fitness comes into play. You must stay strong mentally when times get tough.

When Tyler Perry was sleeping in his car, he was still focused and mentally strong and kept on writing screenplays and creating characters. When the record labels were dissing Jay-Z, he stayed strong mentally and started selling his records in the street.

So just remember: When you are having a craving for that afternoon soda, stay strong. Your body is only as strong as you are mentally. When you're having a tough workout, tell yourself you can do it.

Staying mentally sharp as well as working hard will enable you to reach your goals and become the successful person you are supposed to be.