It depends. Mostly I care, a new baby is a big deal, I think about how it will affect them, what the child might be like, the fact that I will probably still be spending time with that child in ten years.

Holidays I care if they’re interesting. If someone goes somewhere I’ve always wanted to go I might have questions, if they’ve been somewhere I’ve been I might chat about what I liked. But when people try to tell you a detailed recount of some trip, it can be very boring. My parents are particularly bad at reminiscing together while notionally telling me, so they keep going “where was it we ate the second day? No that was the other place” it’s awful. But it’s a chance for them to feel happy about their holiday again, so I try to be patient, and I remember how many times my parents pretended to be interested as I explained how I was doing at some computer game or whatever.

But to answer your question, it sounds like you care less than most. But everyone cares less than the people who’s life event it is. There’s lots of scenes in comedies about people hating hearing about new babies, or being forced to look at holiday photos. So you’re not alone!