Thirty years is a lot, I've only played for 11-12, but I would have given it up infinite number of times if it wasn't such fun. Playing guitar, for me, is playing with the guitar, with my mind, with my soul, with God, if you will. That can never get boring. Don't just play from your brain or what your fingers like.
Always take bites of theory and chew them until you can easily digest them, you can never learn enough. Go crazy every once a while (with a guitar, that is). Also, try other instruments.