I can't help but chuckle when I read your title, as I "hear" it with a Scottish brogue for some reason. So I've laughed a few times, as I keep coming back to your post because it resonates with me. Fact is everyday you are better than you were before. That doesn't mean that certain aspects that you thought you'd learn won't be forgotten. Or that that effortless feeling you had going up and down your pentatonic scale yesterday, is gonna sound like crap today. But if you're consistent at working on the various aspects that make up your practice, you are getting better. It's kind of a up three steps, down two steps with a few ten step sprints thrown in occasionally. Take the time to record your practice sessions and compare them to one another now and again. You'll hear the improvement.