More simply put, proverbs are words of wisdom that have been quoted and re-quoted over time. Some examples:
Two heads are better than one.
Look before you leap.
Better late than never.
I personally use that last one quite regularly as I have a problem with arriving at work on time.
So I'll shrug and say "well, better late than never" meaning, "I'm here now and can get things done. Would you rather I'd stayed home and then nothing would get done?"