It always seems impossible until it's done.

Work ethic is important, because, unlike intelligence, athleticism, or charisma, or any natural attribute, it’s a choice.

You're not in competition with anyone but yourself. Outdo your past, not other people.

In order to become better than anybody else you must first become better than yourself.

Whenever you find yourself doubting how far you can go, just remember how far you have come.

Hope might be a good breakfast, but it makes a very poor dinner

I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times.

Don't expect to be good at maths or understand things straight away. Be patient and persistent. Rome wasn't built in a day, but they worked on it every single day. 

If you can understand just one thing thoroughly, then you will understand everything.

There is no elevator to success, you have to take the stairs.

Failure is NOT your destiny. Failure is the key to success.

The bad news is time flies, the good new is that you're the pilot.

The greatest enemy to human potential is your comfort zone

Everything you want is on the other side of fear

The boxer is not afraid of being knocked down, he is afraid of not being able to get up again.