Lovely piece, Clive. For me, there's one other essential component: expertise. Had Thomas Brock not been a microbiologist, his curiosity may have led no further than "Huh!" when the park ranger told him it was algae. He knew where the gaps in his field were, so to speak, and his curiosity had a disciplinary fervor.

Mark me down as a proponent of expertise in "useless things." You never know what use may come of it after all.