Now that you mention it, I "think" the only time I was on one was a short night hop from L.A. to San Diego on an almost empty plane after I missed my earlier flight. Never looked out at the terminal to see what it was, just got on and away we went. Kind of hard to experience the 747 (if it was one) on such a short hop. By the time I started taking longer vacation trips it was all 757 twin engine stuff.
I once flew a 747 from NY to LAX, was in my USAF Sgt uniform. The bird left NY late because of a problem, there were 28 passengers on it. The stewardess came up and told me that there were free drinks in the lounge in the back of the plane, which had a piano bar back then.
I shared chat and drinks with a Tennessee Vol babe for a couple of hours.
What a good memory.