I have been locking up all sorts of bikes outside in the big city for more than 30 years. The only place I have had one stolen was from inside my house, while I was at home and awake.

When I am out on tour I sometimes won't even use my relatively thin combo cable lock when I sleep at night. That same lock is what I use if I feel the desire to lock while I do something like shop for groceries or have a meal indoors.