What makes you happy? Are there material objects that bring you happiness? What about music or art or food? Are you happy because of the work you do or the people you associate with or because of your hobbies or because of some great past memories?
What? I'm assuming you ARE happy. Perhaps I should have first asked if you are. Well, what's the answer? Are you a happy person? Do you share that happiness with others? (Sharing happiness can also bring you happiness).
I think that happy is one of those wonderful things that is very easy to share. If you are smiling it invites others to smile as well. If you seem to be happy and pleasant, I'll bet you will find others picking that happiness up from you!