Whoa,
Bęthberry! You've been digging!
This thread seems to partake of some of the same information as "what breaks the enchantment", with regard to Elves. So, is it that Sindarin Elves are less serious than Noldor and Vanyar? Or is it that Elves can frolic on the surface while keeping a very grief stricken interior below the surface? Hmmm...... I might take a guess, but I'll wait....
As to Tom Bombadil (why oh why did you have to bring that conundrum into this discussion?

), who knows? Probably. Elves seemed to be aware of him, eh?