Well, the thread subtitle only gives you a choice of big or small things to be happy about--but I'm pretty sure I've often been happy about medium things. A productive day at work seems sort of medium, as opposed to finding a tube of toothpaste in the cabinet so I don't have to buy a new one, which would be a small thing, or meeting Robert Plant, which would be a big thing.
I don't know if the first Ledzep, sorry, THE FIRST LEDZEP, sees it that way, though.