I can, therefore I am.

You never know what motivates you.

To know oneself, one should assert oneself.

Be thine own palace, or the world's thy jail.

Go for it now. The future is promised to no one.

To be a good loser is to learn how to win.

Know or listen to those who know.

Either you run the day or the day runs you.

It's always too early to quit.