Rude People or Smarter than me?

I'm walking into Albertsons to stock up on some supplies for my sunday BBQ. Don't need too much. A couple chickens and some fruit. Its sunday afternoon and as usual, had to park in the back of the lot, which was full. On my walk in, I see an old man approaching with a severe limp trying to get to his car. As he gets closer I can read his t-shirt. "The Marines; fixing the Armys mistakes since 1775." Probably an old school bad ass. Dudes, probably been rolling with shrapnel in his ass since Iwo Jima.
Anyways, im in the store, I get my food and I head to the express lane. 15 items or less the sign reads. I look in front of me and notice the fat obese lady with the 1984 billy idol haircut with an awful lot in her cart. As her sausage paws grabbed her items, i start to count. 1, 2, 3, 15, 26, 29. Slut.
All her stuff is on the belt and she turns to the checker and says, "oh, this is the express line, i didn't know." Likely story. Your first time in a grocery story lady?
I have 4 items. Never did she give me the courtesy: "you dont have much, would you like to go ahead."
Did she know what she was doing? I incline to think so. Rude, at the expense of other peoples time. She then walks off.
After i buy my goods, I head out to my car 100 yards away. Guess who's in the first parking spot? The handicapped spot? Ms Sausage fingers. 100% able bodied person unloading her crap. Handicap tag on the rearview mirror and all. Bitch are you handicapped? Do you stay above 3bills so you can claim being handicapped. That stuff just pisses me off.
Things are now coming together. She knew damn well she was in the express line and she knew damn well she didnt need the handicapped spot. The person who needed that spot was the old man who took a mortar shell to the ass 60 years ago and hasn't been right since.
Am I the dumb one? Should I be saying screw these people I don't know? Should I worry about myself and do things like abuse the handicapped system or cheat and get in shorter lines at the market cuz my time is more valuable than yours? I don't know.
What I do know, is that I saw Sausage Finers drive away and she took her handi-tag off her rearview mirror. Maybe she ate it.