Life is like a race. What matters is not whether you have a headstart, but rather if you reach the finish line.
If you get tired, keep running. Don't quit or drop out. Convince yourself that there are better things up ahead, better things in store for you.
Think about your friends' reactions when they find out that you've won the race. Picture the Trophy that you'll hold, the awards you'll receive.
Winners don't quit. Don't give up.
~Me
(Paraphrased from lots of sources)