I used to have similar things especially in teen years. It is since then that through various forms of therapy I have learnt to believe that the elated blissful feelings I have had have been a response to very early disruptions.

They used to come out of nowhere and I didn't know what they were but I have traced the source of them which I know now are from my early disruptions through various forms of therapy alternative and otherwise.

I still have the blissful experiences but I believe I know where they originate. It is just learning how to control them and ensure that they do not affect my functioning.