All that anticipation leading up to an event that isn't as great as you imagined.
Not that I have problems coming up with ideas. I've got dozens of 'em running through my brain every day. The problem is chasing down one of those ideas and seeing if I can do the hard part - turn that idea into a story.
Stories are much bigger than ideas. Stores take a fluid, boundless idea and attempt to shape it into something concrete. They require developed characters that have wants and needs that are then thwarted by a problem. They require work.
And that is where the shiny new idea loses its luster. Work. Fun work. But work.
So yeah, ideas are like kisses. Exciting when in your head, but not quite as exciting when they become real. Because after that moment of plucking the idea out of my head and placing it on a page, I have to flirt with it, date it, and then ultimately commit to it - or set it free while I continue to search for "the one."
So who am I to my story ideas? A loyal girlfriend? Or a commitment-phobe?
