@CalamityJane,
I can't imagine you riding a bike Cal.
Tell me, if you will, when you were finding those bicycles convenient, and you must have ridden one to find out the quality of the convenience and remember it sufficiently well to inform us of it, did you dust off the seat before mounting up upon it and peddling off. Or stand up on the pedals. You wouldn't have known who had previously sat on it and if it was a busy time it might still be warm. Possibly moist.
Personally, I would choose which bicycle to pick up based on the general appearance of its previous rider and her technique. Those in the Bonnet Series for preference. Ursula Brangwen types.
There's a great sequence in Amarcord which shows some peasant ladies mounting bikes.