I second that. The time when their interests bore you to death is so damn small. The time they need a diaper or breastfeed is so damn small. It is intense and hard, but then, just some steps down the road, you just sit there rewatching Sailor Moon instead of Peppa Pig and spending time together becomes actually cool and interesting and it feels like you have a great person around. You read great books together instead of looking at books that go like "this is a caterpillar. It likes apples. The caterpillar bites into an apple." You make up stories. You draw together. You roughhouse. You just... hang out.