You don't have to be great to start, but you have to start to be great.
If you go looking for a friend, you're going to find they're very scarce. If you go out to be a friend, you'll find them everywhere.
Send out a cheerful, positive greeting, and most of the time you will get back a cheerful, positive greeting. It's also true that if you send out a negative greeting, you will, in most cases, get back a negative greeting.
When you encourage others, you in the process are encouraged because you're making a commitment and difference in that person's life. Encouragement really does make a difference.