Nearly every time someone flakes on me, I take it personally. Like really badly. It's as if they'd rather do anything else than do what they said they would with you.
....
Am I alone on this? Does anyone else feel this way, or am I just a cry baby?
You're not alone. If someone makes plans with you, and then blows you off, it
is personal. How much 'personal' depends on the nature of what happened. If little Joey breaks his arm and is being rushed to the hospital, perfectly understandable. If Mommy forgot that Joey's archery practice got moved up 2 hours, that is not so understandable.
My Internet degree in Psychology says people who do this a lot are Narcissistic.
Not letting someone know right away is pretty much a deal-breaker for me. Sure, things happen, but unless one of you is a card-carrying-Luddite, there is no excuse for leaving someone hanging.
My own worst time with this was my first year as a parent in Cub Scouts. We ran a fund-raising booth at a local festival. The guy tasked with setting up was complaining about all the work involved, so I volunteered to take a day off and be there at 8:00 am to do my part.
At 8:30, I call the guy asking where he was, and around 9:00 he calls back, acting all surprised that I showed up on time. This is the same guy who would arrange for the Pack to meet at 9:00 for travel to an activity and show up at 9:30 "Because no one ever shows up on time, and I don't want to waste my time waiting" (Note he says this straight faced to every other parent who had been waiting for his family for 30 minutes; no one else was late.) He never had an apology, worse, he would act like people should know what his plans were, and 'just work around' him.
This person and his family were so bad that when my son went over to Boy Scouts, I told him to pick any other Troop except for the one this family was in.