I had a blonde moment like that last winter. I am blonde, so I have a lot of 'moments' and I do blame it on the hair, lol!
I had a remote started installed in my car, original Mazda parts, but after-market. So anyway, I was just getting used to how it all worked, since my car is a manual transmission, it's not like a regular remote starter. I started my car one morning, to let it warm up, about 15 mins later, I went out to scrape the windows. I opened the door, sat down, put the key in the ignition, grabbed the scraper and shut the door. 5 seconds later I hear "click". I'm like, oh crap!
The thing is, my car won't lock if the keys are in the ignition either, HOWEVER, because I started the car with the remote, and just stuck the key in the ignition without turning it or pressing the clutch to disengage the remote starter but keept the car running, the control unit just though I opened the car to grab something and left again, so it locked automatically. My purse was in the car, with my house key, so I couldn't get back into the house to get my spare car key either!
I did have my cell, so I called my mother who looked up the Mazda roadside assisntance number and then I called them. Before sending someone over to unlock my car, they had to confirm ownership of the car, so they were asking for my registration number, and the VIN number, which I couln't even get at because that info was LOCKED IN MY CAR!!
LOL! Finally, they sent a guy over to unlock my door, and once he did that he checked the serial number to confirm.
To top it all off, the guy was a total smart a$$, and felt the need to tell me that this happens all the time and 99% of the people it happens to are women. I was like, yeah, but I WORK ON CARS FOR A LIVING, you would think that I woud have enough sense to know better, and he just laughed at me and said that it was inevitable. I wanted to punch him.