I can very much relate to this, Zero.
I don't know if it will help, but one thing I've started doing is taking a couple pictures of landmarks around the area where I've parked--for instance, one store I go to that gets pretty busy has 3 different entrances, and each one has different landmarks by each door. When I get out of my car, I'll snap a pic of the landmark at the end of the row (such as the car shop) and when I get to the door of where I'm going, I'll take another pic from the front of the row that tries to catch the landmark in that background, then make a written note on my phone of any other things to remember (row number if they have them, a lamp post 3 rows to the left, etc.)
I don't think that's a sign of getting old--I honestly think parking lots are just getting too crowded and confusing!