Thanks for replying!

I don't have a counterfactual universe where I could alter certain factors about the weekend to see which of those factors is responsible for me feeling drained.

This is certainly true. But I was hoping that you might be able to tease out the main differences between that LW weekend and occasions where you did not feel drained. It could even boil down to something like "I happened to be feeling stressed about something else during the community camp, which could explain why I felt drained more easily".