I tend to shift whenever winds or slope change. As a guess... on a 30 mile rail trail ride, this means I probably shift 10-30 times depending on the specific trail, weather conditions, and how warmed up or tired I am. The guy I ride with on many of my rides doesn't shift quite as much as I do,

For me, if I stuck with one gear, I would find it distracting to periodically end up mashing too big a gear or spinning out a too small gear, but if it works for you, then enjoy it.

Of course, now I'll probably have to count my shifts on my next ride just to see if my guess is accurate.