There are quite a few who say they're mountain bikers. A few times I've asked and pushed to learn they're talking about the bike they bought when the sport first hit popularity, and these late 1980s and early 90s bikes usually hang in the garage or basement.
Some of these people become temporary mountain bikers again when they show up against trail projects at Sun Prairie, Middleton and Blue Mound meetings. They say or shout "I'm a mountain biker too!" before they shout why they can't have trails terrorizing their back yard. The same questions that have revealed the sort of mountain bikers they are usually reveal they don't know what single track is. I pushed it with a few and learned the trails they claim to ride and love - the ones where we shoud go - are Indian Lake and east side of John Muir trail head probably closed 20+ years now.