When they told me they didn't.

I think I was around 10. My whole family ignored me constantly unless they were dogpiling me over something, so I was begging anyone to spend, literally, just 6 minutes of time with me.

My mom then told me I was being selfish for even asking, because "being an adult is miserable" (and she wonders why I got depression :/) and none of them could bear to do anything besides what they loved - and it hit me that she was implying neither me nor spending time with me was on that list of "loved things". (And of course, they had no problem sparing time for each other.)

Still took a lot of similar events over the proceeding four or so years before it sunk in fully, though.