I remember my first bikes with a lot less affection than you do. My first, in the late '40's, was a full size 26" balloon tire "girls" frame that was a hand-me-down from several older cousins. It was crude, heavy and a real fight to get up any significant hill and my parents house was on a significant hill. When I was 13 I got a new J.C. Higgins (Sear's house brand, made by Roadmaster) that was also a single speed balloon tire 26" but at least it was a men's frame. Also heavy and a fight to climb with. I wanted a 3-speed "English Racer" but my parents thought it would be too fragile. Perhaps they were right.
Simple? Yes. Rewarding to ride? Not so much.