Kids are going to be kids. When they're your kids or in my case....kids in my family (niece and nephew), then it's a whole different ball game when they misbehave or melt down. My niece, who is in her last semester of high school...."melted down" frequently before bedtime when she was around 2-5, including when my sister would be entertaining. We always knew it was coming, and she grew out of it. It never lasted long in front of anyone because my sister would scoop her up and take her up to bed to lay with her...sooth her until she feel asleep. This was always at home though...never in public. But still...I'm sure some adults were like..."omg...this kid!"
I almost always feel for parents when a kid is misbehaving in public, but there are occasions when the parents are clueless to everyone else around them. One flight comes to mind ....it was a vacation to Mexico several years back and we were sitting in business class in a 2-2 configuration. We were in row 2, and there was a family of four behind us....the parents (in their late 30s/early 40s I'd guess) sat together and seated their kids, a boy and a girl behind us....guessing again, but probably not far off....girl 7, boy 5. It seemed like a fun thing for them...we could hear that they were excited to be sitting without the parents. Any other time I've seen this type of family....one parent sits with one of the kids.
The kids started "playing" and one of them....the boy, had a metal box filled with little cars, action figures....etc, that he proceed to shake, pound them on the metal box...etc. His sister started to yell at him to stop (I was on her side), and they were just acting up in general, and then the little boy started kicking the seat...my seat. The parents were *oblivious* to this...and I'm not exaggerating. The husband was working on his laptop and the wife was watching a movie with headphones in. My husband leaned over and tried to catch one of the parent's eyes to be kind of like..."can you guys referee a bit?" kind to deal....but they did not respond. There were sighs and moans in the entire cabin. DH finally got up and spoke with the flight attendant (mostly for the seat kicking)...and she spoke to the parents just saying that the kids were making a lot of noise and kicking the seats....the woman was very blasé about it, said one thing to them....and then the kids pretty much continued acting like unsupervised brats (again...mostly the boy). The parents just came off as very entitled to us. At the end of the flight when we all got up to get our suitcases....there were lots of eye rolls and shaking heads between other passengers. A couple of dirty looks towards the parents for sure.
It was one of those...."what were they thinking?" kind of moments....and definitely rare, but those experiences stick with you. DH and I almost always smile and coo at babies and small kids....even though we didn't have any of our own...we like them. But we also frequently think of those kids any time we're boarding a flight...lol.