Expect problems and eat them for breakfast.
To know oneself, one should assert oneself.
It's always too early to quit.
If you think you can do it, you can.
You never know what motivates you.
Know or listen to those who know.
Who seeks shall find.
The dog that trots about finds a bone.
If you can dream it, you can do it.
If you're going through hell, keep going.
I rate enthusiasm even above professional skill.