I think you forgot something

Driving back to work from lunch today, sitting at a stop light I look to my right and up at the giant black Dodge pickup in the next lane over. Driver was a barely-old-enough-to-drive looking guy. Normally I would have wondered what he was compensating for with that gianormous truck, but my attention was quickly grabbed by the hot pink thong pair of panties hanging from the rear-view mirror. I've seen people hang a lot of different shit from the mirror, but a thong? Seriously, a hot pink thong... This is where I find my brain is capable of multi-tasking when it shoots off in a million directions of thought all at once... Some of the thoughts were:

Were they recently worn?

Did he take them right off of her/him (the owner) and hang them up?

Did he find them later and decide to advertise his conquest by displaying his thong trophy?

Did she/he (the owner) give them to him?

Did she/he (the owner) know they were missing?

This kind of reminds me of clip from one of my favorite shows, The West Wing. In season 7 of the West Wing, the Communications Director, Will Bailey, and the Deputy National Security Advisor, Kate Harper, hooked up in one episode and then in the next....

WILL
Hi.

KATE
Hi.

WILL
I have a thing of yours.

KATE
My Pyongyang book, good. I tore up my whole office looking for it.

WILL
It’s not that.

KATE
Really?

WILL
Really.

KATE
It’s in a blue binder. It may not be...

WILL
Nothing in a blue binder.

KATE
Are you sure? I mean, picking it out...

WILL
It’s a bra.

KATE
Oh, okay.

WILL
I put it in a padded envelope, which seemed appropriate.

KATE
Really?

WILL
You want it now?

KATE
No! No. Yes? [pause] It’s in your office?

WILL
It is.

KATE
You keep it.

WILL
Permanently?

KATE
Mail it to me. Your home address is my home address.

WILL
You don’t think that’s a little complicated?

KATE
It is, isn’t it?

WILL
I’ll hang on to it until we...

KATE
Okay.

WILL
We’ll get better at this.

So, now that I've rambled incoherently...here's my question...how do you leave some one's house, hotel room, car, or whatnot and fail to notice that you forgot your underwear and/or bra?