I know that feeling a little too well. More "wasted sessions" than not (as in, maybe a couple times a year I *didn't* feel that way?). That's why I quit all individual therapy. If it's just every now and then bring it up the next session if nothing else more pressing comes up and see if you can come up with a plan of what to do or at least feel as though you are making progress in the grand scheme of things. And if you're not, well, maybe it's time for a different approach.