It's always too early to quit.
If you've got a talent, protect it.
Leap, and the net will appear.
If you're going through hell, keep going.
Begin to be now what you will be hereafter.
Be gentle to all and stern with yourself.
The dog that trots about finds a bone.
I can, therefore I am.
Always desire to learn something useful.
After a storm comes a calm.
I'm someone who's done the opposite of whatever the received wisdom is, to keep your career going into your 50s.