...What?

I love mail. I love email, voicemail, text messages, IM's, and snailmail. I love it all. I get really excited when I walk into my mailroom everyday and open up my very own (well, I share it with my roommate)mail cubby. I love to receive catalogues, and prefer to shop online so that I get those little slips of paper that inform me I have a package - oooh, oooh, and sometimes I even get a KEY to a big ol' cubby that has my package inside of it!!!
I love the fact that at 1400 everyday, my mail is in it's cubby, waiting for me to come and get it. Today at 1720 I went to the mailroom to get my Joy and to my surprise there was a big, fat, sweaty mailman in there putting mail in their respective cubbies. I was confused because

a)the mail is supposed to be delivered by 1400
and
b)what the fuck is a USPS employee doing working after oh, 1500?


So I asked the guy what he was doing there which may have discredited me because he was, obviously, delivering the mail, but again, I was confused (refer to a) and b) above). Then, the panic set in. I was relying on my mail being there!! *terror* Maybe it wasn't 1720, maybe it was 1320 and I was in a parallel universe. *dizzy* Was there a "mail emergency" earlier that prevented the delivery of my mail at its appointed time of 1400? *dread* Would my mail arrive in an unharmed state? The possibilities became instantly endless.
Slightly exasperated, I asked him if he generally worked this late (mostly to test my theory about the alternate universe) and his reply was,
"We work until all the mail is delivered, Ma'am."
Whoa. I am in an alternate universe.