The oddest thing happened to me... Was it outside the boundaries of propriety or am I just too uptight?

I was having a lovely snooze on Sunday morning at 6:21am when the phone rang (the special ring when there is someone at the front door who needs to be buzzed in)... Thinking it was a friend in need, I ran from my warm bed to the kitchen to answer the phone.

It was my neighbour, with whom I have only exchanged polite "hellos" in the hallway. He said nonchalantly, "Hey, I left my keys at work. Can you let me in?"

"PARDON ME?"

Well, since I didn't recognize his voice, I said I would need to come and open the door to ensure I was not unwittingly letting a stranger into the building at dawn to torturously murder an unsuspecting tenant. I was very groggy, but I left my apartment and went to the main entrance and tried to focus on his face before I let him in. He was there with a woman and simply said, "Thanks, man..." and wandered into his apartment - which was oddly unlocked; who does that nowadays?

So here's the thing: Isn't that rude? To wake up someone who you barely know at 6:21 on a SUNDAY?

Or maybe it's just me?