I don't know if I'm the only one but I have a fairly significant amount of trepidation every time I come up to an automatic door. They're rigged to not open until they're sure that someone is really there which translates to - you have to be pretty close to them. I'm always pretty afraid that they're not on and thus not actually going to open when I come up. And if this happens then I would just continue walking and run straight into the door. I've actually seen this happen so I guess my fears aren't completely unfounded but the thought does go through my head every time I walk up to one. "Oh no what if it isn't really going to open?!"