Do not count your chickens before they are hatched.
If you choose bad companions, no one will believe that you are anything but bad yourself.
Facts speak plainer than words
Your birthday is the vintage of your wine; the mark that warns you of your future.
A doubtful friend is worse than a certain enemy. Let a man be one thing or the other, and we then know how to meet him.
Every man carries two bags about him, one in front and one behind, and both are full of faults. The bag in front contains his neighbors' faults, the one behind his own. Hence it is that men do not see their own faults, but never fail to see those of others.