We all have two lives. The second begins when we realise we only have one. 

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

There are no bad mistakes in maths, only discoveries.

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

Work on your weaknesses until they are your strengths and work on your strengths until they are second nature.

Time is your friend, impulse is your enemy.

Knowledge is of no value unless you put it into practice.

Success is the sum of small repeated efforts, day in and day out.

Don't put off until tomorrow what you can do today. If today you have no time, it means tomorrow you'll be too tired and the next day you'll be something else.

Success can never happen without the journey (struggle).

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

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

Don’t be afraid to work hard and find out how good you can really be.

Be strong enough to stand alone, smart enough to know when you need help, and brave enough to ask for it.

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