I once told a counselor that I had these occasional episodes where I felt wonderfully happy for no reason at all. I brought it up because the sensation was alarming, unnerving and uncomfortable. She told me that lots of people experienced that feeling and that it was normal. The first thing out of my mouth was: "That is the creepiest thing I've ever heard of!" Sorry to say that this creepy feeling happens even less than it did but it still makes me profoundly uneasy.