Several years ago the transmitter for my car alarm died. Before I got around to changing the battery on it the plastic loop by which it would hang on my keychain broke. While my car has an alarm, I had put it permanently into valet mode a long while back because it was just a pain. I would use the power lock button to lock the doors, and the key to unlock the door, so at some point I practically forgot I had an alarm and took the transmitter off my key chain.
I almost always carried a bag of some kind so I just kept the broken transmitter in the bag. At some point I stopped carrying that bag, got a bigger one and didn't move the transmitter over to it. Then one day my car battery nearly died at work (it wasn't dead, but didn't have enough juice to start the car), but I got it jumped and went to get a new battery installed. The tech asked for the transmitter and I didn't have it, but he was able to get it into valet mode (I now know the trick as well but didn't at the time) to get the job done.
At home I dug around and found the transmitter(s) and replaced the batteries in them. I took the one with the good plastic clip and put it on my keychain but never used it. I always used the key and even though my keys are always on my person I somehow completely forgot I had the thing. Flash forward two years to last week's big snowstorm. Work closes early because the roads are getting dangerous, I get out to the car and the battery appears to be dead. This is that same Sears Diehard 7 year battery from two years ago, but I figure I must have left something on to kill it (I hadn't).
I get a friend to jumpstart me before he heads home, but then we can't start the car because the alarm triggers and kills the starter. I don't (think I) have the transmitter, and another friend manages to get it into valet mode somehow and it starts. He tells me how he thinks he did it, but he wasn't sure since he was doing all sorts of things. I get home finally after an hour and a half in the snowstorm, pissed off and tired going mad looking for my transmitter. The wife finds one in a drawer (where I had put it two years earlier) so I decide to start taking it with me just in case this happens again. The plastic clip is broken, so I have to keep it in a bag.
I make it through a week of work without incident until I have to drop my daughter off someplace today. I don't take the bag because I use it for work. I think about it while I'm in the car, but its been good all week so I forget about it. I walk her in, and give her my phone in case she needs to call us earlier than planned, get back to the car, open the door... there are no lights on the dash, turn the key... nothing, its dead. I get out and pop the hood and find the battery terminal connectors are both loose. I don't have any tools, but there isn't much corrosion on them so I just turn the connector till its as snug as possible. I get in and it starts right up.
The wife's birthday is coming up, and one of the main reasons I dropped off my daughter today was as excuse to go out to pick up a card. I'm a little worried about stopping on the way home since I no longer have the phone and don't have the transmitter but decide to anyway. I get the card and back to the car, open the door and the alarm goes off. I jump in and try to start the car but the ignition is already killed. I try the trick my friend told me to get it into valet mode over and over different ways, doesn't work. The alarm is going off, there's a howling wind, my inspection is out of date so I give up, go to a pizza place and ask to use the phone.
I wait for the half hour it takes for the wife to pick me up and thank the pizza guy for letting me shelter out for a while. I hit unlock on the transmitter with the broken clip the wife retrieved from the drawer and the car starts right up. At home I clean and tighten the connections on the terminals, dig out the alarm system instructions and review them. We have a nice lunch and I go over how to use the system with the wife. I mumble something about how I really need to get a new transmitter without a broken clip so I can keep it with me. She's silent for a moment, points her finger at the keychain clipped on my belt... "isn't that the other one on your keychain?" And so it was, right there the whole time, through the snowstorm and the pizza place.