hi, welcome to the great and secret show.
I somewhat understand you when you tell of sitting and feeling the energy saturate you. Its happened to me on some occasions when I'm sitting watching tv, in a cinema or just when I read the boards with no concious thought to 'do' reiki the energy just flows, mostly over the back of my hands and fingers, sometimes down my arms, across my chest crown, forehead and chin now. Funny.
long may it continue and have fun with it.
ciao