At the company I'm working for, temps' keycards get automatically disabled every six months.
It's a rote thing and I know how it works by now, but it still raises the hairs on the back of my neck. I've got a visceral reaction to coming in and finding myself locked out, something left over from the job last year where I just came in one morning (a 30-mile drive for a 6 AM report time) and they told me I'd been fired.
I know that was an anomaly. I've only ever been fired from that one job; it was a fluke, and by now I know about the security procedures here and can think of things like "Oh, it's the first day of the month that marks one year I've been here? Yeah, that sounds like an expiration date."
But even though I know, calmly and rationally, that it's no big deal and I just need to go up to the front desk and get my account reinstated (and damn it, the guys I work for now are decent human beings and wouldn't do that to me), I still get that sinking feeling in my stomach; maybe it is happening again.
As traumas go, I suppose getting fired from a crappy temp job is a pretty minor one. But it definitely left an impression with me.