Check Engine light cleared itself

[Bulk]

I replaced the left bank Cam cover a couple of weeks back and long story short I got the check engine light shortly after driving it for the first time. I left the cam sensor gasket loose during install so that it could seat properly and forgot to tighten it down. I tightened that down and everything seemed to function properly again. I was sure that that was the cause of the check engine light as that is all I replaced and it was an obvious cause...... (+ my diagnostic software was still on its way from Romania) - I may have even got a dash message "Engine vacuum" or something like that...... or maybe I was dreaming

About a week later the check engine light just extinguished itself. So to the gurus. Does it realise the error has been rectified after a certain number of cycles? or has it just given up on trying to get me to take notice of it?