NEVER.

NEVER quit. 

Pain and suffering are always temporary. And failures don't make you a failure. Quitting does.

NEVER judge a book by its cover. 

Don't judge anyone before you know their character and present circumstances. 

NEVER assume anything about someone or a situation, unless you know without a doubt that you are 100% correct. 

NEVER underestimate anyone or look down on anyone. 

You never know what an individual is capable of doing. 

There could be a world-renowned author, successful business leader, or another Bill Gates in your mist, and you don't even know, because the individual isn't there yet.