OK, I guess I have the exception that 'confuses' the rule. Or, a couple:
1. The other day, I took my nephew (9) to the local convenience store; it was 2 blocks further than we've walked in over a year. Each way. But he wanted a Honey Bun, and I wanted chocolate milk, so....
2. This evening, my neph wanted to "go for a walk". Too chilly/windy for him to ride, and I had a BAD day (shoulder's still on fire, been home 4 hours), but we went walking. Odd thing about the block we live on -- all the way around it is a MILE! I measured it a couple years ago!