It's always too early to quit.
Problems are not stop signs, they are guidelines.
Begin to be now what you will be hereafter.
To know oneself, one should assert oneself.
Do not weep do not wax indignant. Understand.
Who seeks shall find.
Only the educated are free.
Well done is better than well said.
Go for it now. The future is promised to no one.
Leap, and the net will appear.
I wrote somewhere during the Cold War that I sometimes wish the Iron Curtain were much taller than it is, so that you could see whether the development of science with no communication was parallel on the two sides. In this case it certainly wasn't.