I often feel the same way. I don't miss the stress of being a student, but I do miss having classes- learning new things, engaging with others, pondering and discussing ideas- exercise for the brain!! It feels like opportunities for this, or time to take advantage of such opportunities becomes difficult to add to the current juggle of responsibilities.

I'm applying to teach a course next semester (fingers crossed!!!) one night a week, and since I've seen the job opening it's made me really excited thinking about it, not just from the monetary view, but being in that setting again.