There's a difference between understanding and accepting. My husband doesn't understand a lot of my feelings but he accepts them; they're there, they're me, and he's okay with that. I don't have to make "sense" to him (although I'm trying to get him to understand that because he doesn't understand doesn't mean I don't make "sense" :-)

Practice a lot of shrugging and head shaking? If you don't understand something but it's not about you, shrug? Some people over identify with football teams, some with cars, some with animals, etc. My husband bought our TV way back to coincide with the Olympics; I could care. I watch NCIS on Tuesday nights and he watches Dog the Bounty Hunter on Wednesday and neither of us likes the other person's shows. We have a small house with only one "sitting" area so the other person goes upstairs to the bedroom and reads when our partner's shows are on.

That's a good option when one is getting annoyed or angry because of what another person is doing. Leave. Yes, often we are in our own space and shouldn't "have to" leave but using Time (it will pass and things will shift/change) is a very good, inexpensive method for dealing with any immediate emotional problem. May be temporary but gives space for us to work with ourselves so we can deal with whatever in some other, better way in the future.