I hear you guys, and I promise I'm not slapping a "definitely introverted and sensitive" label on my kid willy-nilly.
Some of the "input! input!" thing he does, I think, is actually about feeling overwhelmed by his own thoughts, like they are too big and complex for his little brain, so that he's reaching out for help sorting through them, rather than like he preferentially processes ideas externally. I suspect (I am prepared to be proven wrong) that some of the information-seeking conversation is more about this and less about wanting to connect with others.
I'm not sure he has any anxiety about me leaving the room and so on. I'd actually say that a good side effect of his intense drive to be joined at the hip to a parent is that he is now pretty relaxed about being apart from us. There has actually been kind of a boom in him wanting to be more independent (this is a mixed bag), so I wonder if this was all part of the same developmental leap. Hard to say. Kids are weird.
I'm doing my best to enforce healthy boundaries about when I can talk about endless science questions, and when I need a little bit of quiet. It's slow going, but I'm doing my best. I also committed the outlandish sin of making a rule that we could no longer read science books at bedtime. It was like they were causing brain fever, and he would lie in the dark and almost fall asleep and then need to know if any of the metals are translucent and why are things translucent and how does it work, and wake himself up again.
