Always desire to learn something useful.
If you can dream it, you can do it.
Who seeks shall find.
You never know what motivates you.
Be thine own palace, or the world's thy jail.
Without hard work, nothing grows but weeds.
The wise does at once what the fool does at last.
Well done is better than well said.
Be gentle to all and stern with yourself.
Know or listen to those who know.
It's amazing that something only an atom thick can be an impenetrable barrier. You can have gas on one side and vacuum or liquid on the other, and with a wall only one atom thick, nothing would go through it.