I just experienced the thrill of my first colonoscopy this past week. As I prepared for the "event" and they put me on the table, they said they were about to administer the "happy drugs." I've never been put under before and only once taken a painkiller stronger than ibuprofen, so I had little prior experience with these things.
They worked in that I don't remember anything from the procedure (thank goodness). I awoke after it was all done. But I didn't have any buzzy/happy feelings, when I woke up I was wide awake and alert. So I still haven't experienced any "high" type feelings in my life (never been buzzed or drunk).
But what I did notice what that I was completely pain free. I normally don't feel a lot of pain, but have assorted aches in my lower back and in several joints. They are constant companions, better some days than others. As I progress further over 50, more little aches are being added. But for about two hours, they were gone.
Wow, did that feel good! I had forgotten what it was like to be ache-free. No muscle stiffness either. My wife picked me up and we went out to lunch. I walked a few blocks, it was wonderful. I'd love to ride my bike in this condition.