The dog that trots about finds a bone.
Do not weep do not wax indignant. Understand.
By failing to prepare, you are preparing to fail.
What you do today can improve all your tomorrows.
Who seeks shall find.
To know oneself, one should assert oneself.
I can, therefore I am.
You never know what motivates you.
Well done is better than well said.
The wise does at once what the fool does at last.
In hard-core science fiction in which characters are responding to a change in environment, caused by nature or the universe or technology, what readers want to see is how people cope, and so the character are present to cope, or fail to cope.