When I first got my Reiki 1, to be honest I felt nothing much for a while when giving a treatment, and like you, just happier after receiving. After a while of treating myself and others I began to feel a tingling sensation and heat at the palms of my hands. After Reiki 2, the sensations became much stronger and I started to see more visuals and colours while giving and receiving - now I usually get feelings, impressions, visuals and physical sensations when giving or sending. I've found it to be really healing and helpful and I'm really looking forward to my level 3 :)