Rob,
A bicycle is indeed a good deal. One of the most efficient modes of transportation. A single speed transfers something like 99% of the work to the wheels. Derailleurs lose a bit but still well over 90%.
I'd say off topic, but I'm not sure what the topic is anyway.
Not off topic at all: we are talking bicycles here!
I had a lovely red Raleigh Lenton in 1953. It came sans gears, but I soon convinced the money sources to let me add a set of Derailleurs (first time I realised how that's spelled!) and they were so cool! Much more tech-looking than the thick, internally adjusting Sturmey-Archer alternative. My set came with three gears; I did end up with a Campagnolo changer arm, but I never managed to get it to function with the DR set of cogs. Naturally, I took up an engineering apprenticeship which wasn't a bright idea designed to last.
The rest, as they say, is history, but don't look for a historian who can remember this particular slice.
Rob