Expect problems and eat them for breakfast.
Things do not happen. Things are made to happen.
The dog that trots about finds a bone.
Without hard work, nothing grows but weeds.
To know oneself, one should assert oneself.
You never know what motivates you.
Begin to be now what you will be hereafter.
I can, therefore I am.
If you're going through hell, keep going.
It's always too early to quit.
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.