Obviously, we don't always know what is going on in their world either. I can give you an example I just dealt with today. It's a very long story but lets just say I am mentoring/life coaching/counseling a teen girl who has had an extremely difficult life. Like you think of some of the worst things that could happen to a kid and she's been through it. I am friends with the family and for whatever reason, she adores me. We are extremely close. We obviously don't live together or anything but at this point it's sort of like I've partially adopted her in spirit.
So Sat night, she ran into the boy who sexually assaulted her for several months last year. It freaked her out and made her feel really uncomfortable. She also found out someone she thought was a good friend is actually still good friends with him despite knowing what happened. Then today, her family took her and her niece to the zoo. She freaked out thinking about it and said she was a total jerk to her aunt (guardian), her aunt got upset, they fought and she spent most of the afternoon just sitting at the car by herself. For whatever reason, she refuses to talk to her aunt about anything that happened. She just doesn't feel comfortable. So to the aunt, this appeared like the kid is just in a total **** mood for no reason and is being difficult despite them being nice, taking her to the zoo, etc. I am sure the aunt thinks she is so ungrateful, etc. The reality is that the girl is in a situation she's totally unprepared for, dealing with emotions she can't process, etc. She feels really bad about how she treated her aunt but she also has her head spinning right now about who she can trust, who is really even her friend, etc.
I am not saying that any of your kids have things that heavy on their mind but they might or things that to them seem equally as weighty. Or just their hormones are going and they literally can't get a handle on them. I always try to focus on the situation/action and not the person. Someone may make a mistake, do something disrespectful or find themselves in an impossible situation but that doesn't make them a bad person, a disrespectful person or a broken person. Not always easy, but a healthier way of looking at things.