The only thing I've noticed is that when "newbies/junior members" open a thread, in most cases the did not leave any post after they've opened it.
That actually a pretty common thing across various forums; people register on forum asking help for some specific issue or question they have, and after getting an answer, in majority of cases they just disappear and never come back. So yeah, nothing extraordinary there.
I did the similar thing on some other forums as well, disappearing after getting hep with specific problem I had, but at least saying thank you/writing few posts before going AWOL is part of basic posting etiquette, which many fail to do.