I'm currently paying off some college bills but once I have that done, I too will be going back to school to finish up my degree. I'm 36 myself, and it's been surprising to realize that what I was interested in back in my 20s is not something that I want now. We grow at different stages in our lives, and if this is what you want, go for it!
However, do make sure you do the research for jobs in this field. It's been really tight in this economy lately and you may find no jobs in sight. Point being, make sure you have a backup plan but go for it in the meantime.