I think you are on to something. Biking doesn't require any special muscles or strength so you can do it purely from memory. With other activities you also need

I think you are on to something. Biking doesn't require any special muscles or strength so you can do it purely from memory. With other activities you also need some physical skills untrained people don't have. When I did kickboxing I used to be able to kick really high but after a few years of not doing it the muscle memory is still there but I just don't have the strength and flexibility to go really high.