I've opened a lot of car doors recently, mainly for my mum who isn't very mobile anymore and really struggles to get in and out of the car and lacks the strength to open the door wide enough when she's sitting in the car.
All well and good, I'm certain you'd all do the same.
Problem is, I've got that used to legging round the other side or going to the passenger side first, I find myself opening the door for people who don't need it...like the missus (I'm sure she's cottoned on and milks it!)