I agree with the view that you are human. Please note though, I've omitted the word "only". Emotions should not be brushed aside.

Yes, there can be groups of people who display the same ones. Those feelings can be conditioned by something lacking in their lives, or developed with positive guidance (parental/relatives/mentors).

I'm in a similar situation, where a family incident has triggered moral issues. What I feel is great disappointment that the person responsible has not/will not apologise. Have other family members offered any sound advice/help, No! In my mother's view, I should apologise instead. The easy way out and not showing the perpetrator that they've behaved in an unacceptable way. This behaviour can most likely be traced back to how she was treated by her parents. I'm totally different emotionally to most family members, another problem area.

The most likely time for these emotions to surface is middle age. We've taken on new responsibilities (partner/children/elderly parents), juggling demands of a career. The flaws in our upbringing surface as we mature, then it's our choice how we act on them. I don't think you're being immature, you are expecting others to have your moral compass. It can be hurtful when you realise that's not going to happen.