It’s silly but it’s true. Especially if you’ve got a package, a ladder, etc. Nobody’s going to hassle a dude carrying a ladder because he’s clearly Doing Something Important.

When it’s a regular old apartment building you don’t even need that. You can just wait until someone walks in and just follow them through. Happens all the time. Which is why I make sure to always pull security doors closed behind me. I’d rather not be the cause of a break-in or worse.