The days after the marathon can be a bummer. After spending four or more months preparing for the big day, there is a bit of a hangover afterward. Your coming down off the high of the day, but your body is trying to recover from the damage you've inflicted on it. It can be hard to walk, and stairs can be torture. You are also pretty spent mentally.
You relive the day a few times, but high fades away. You check the marathon website repeatedly to get your results. Once you get them, you analyze them to see how well you paced yourself, and where you broke down. You check the photo website until they finally post your pics, then you remember how ridiculously expensive they are.
You can't train, so you look for other outlets. What helps is to have your next event planned. If I'm honest with myself, I know I won't exercise regularly without a goal to shoot for. Having a tangible target gives me structure as well. It of course helps to have something to look forward to as well.
So next up is a half marathon in June, with a relay run and a triathlon later in the year. It is also time to get my bike out of mothballs.