I somehow conditionned myself to think "THREE" every time I am about to get out of any door. I don't even instantly remember what are the three things I should check for. It just happens. Sometimes I stand there for second completely confused as to what is wrong when I realize I have not passed the "three" test. Then I have to consciously bring the three items to my mind and figure out which one is missing!

What's funny is that years ago it was a FOUR check, (I had two sets of keys) and when I got rid of one set it took me weeks to recondition myself into the "three" test. I'd be standing on people's doors thinking to myself, it is OK to fail the FOUR test, it has become a THREE test now, get on with it.