I think part of the issue is that the child often knows that the adults reasoning is wrong or even deceptive, and as you point out that will feel unfair. As a

I think part of the issue is that the child often knows that the adults reasoning is wrong or even deceptive, and as you point out that will feel unfair. As a child, I often read until 2-3am, and was just fine the following day (wish I could do that now). Any actual enforced attempt at going to sleep would have felt unfair because it'd have been earlier than I needed. What my parents actually cared about was that I was in my room, and that I got up without being cranky or letting it affect school the following day. It's much easier to "sell" the child on that, by being honest about wanting quiet time and wanting to make sure the child isn't too tired, than convincing them a bedtime they will have secretly violated multiple times without feeling too tired is reasonable. So from pretty early, my "bedtime" was "alone time" as you suggest, with the proviso that if I couldn't get up without being prodded in the morning that was evidence I was taking the piss, and the consequence would be tightening up of the actual bedtime for a while. That felt fair, and honest, and the rules were understandable, and meant I often stayed up way later than my parents would have thought was reasonable, but since it worked, it was fine, and I self-regulated.