Always desire to learn something useful.
Be kind whenever possible. It is always possible.
Be thine own palace, or the world's thy jail.
You never know what motivates you.
Leap, and the net will appear.
Only the educated are free.
I can, therefore I am.
By failing to prepare, you are preparing to fail.
If you think you can do it, you can.
Never complain and never explain.
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.