I am not a kid, and am what you described, except for the " think they know it all" part; I watched videos and read a couple of guides before I did a sherpa'd DSC, but those just provided conceptual introductions to the roles rather than integrated views of the encounter "big picture" so I went in expecting to need to learn. So many LFG posts are KWTD, so few are Chill. If it weren't for r/DestinySherpa I'd probably never have raided at all.