I really don't understand the fixation that it is "bad manners" to wear a hat indoors (obviously not at a formal event, or church, or a really nice restaurant). It's very arbitrary...WHO SAYS it's good manners to remove a hat?? Some person many, many years ago? That's ridiculous. Then again, my family doesn't live our lives by the rules of Emily Post. We do however respect others, offer help to those who need it, give up our seats to the elderly, open doors for other people, speak respectfully to others, and generally subscribe to living lives that promote doing good for others, and treating others with kindness and respect. Wearing a hat indoors has ZERO bearing on that. And are there really people who count how many people they see wearing hats indoors and get up in arms about it? Wow. They must have a lot of free time on their hands.
My 51 year old DH is a professional guy, and the only place he doesn't wear a ball cap(other than those places mentioned above) is when he's in the shower, asleep, or at his job. The minute he walks out of his office, the hat goes on. I have no idea why it's so important to him, but it's what he does, and it's not my place to change it, because it's not hurting ANYONE. It could be that it's because he is self-conscious about his receding hairline...I don't know. It doesn't bother me at all, and I'd certainly never insist he remove it at the table. And Lord help any stranger who would say anything to him, or attempt to knock it off his head. Oh my...it would not be good.
As for cell phones...the only problem I have with them is when someone thinks that taking a non-emergency call, or playing games or checking Facebook or their email when they are socializing in person with someone is more important than the person they are socializing with. To me, that is RUDE and DISRESPECTFUL behavior, and shows that person clearly has no manners, or consideration for others. But a hat on the head? No way...not even a blip on the radar.