Strange, I was never like that Freddie, I've felt like that after my surgery.
I'd say you won't know until after surgery if you will feel better. Since my surgery, I've had my good days..but I feel like I owe that to not smoking. Other than that, personally I've been short of breath, tired, burned out, and my head is 80% of the time a mess, and I am very sorry to use this word and hope I don't offend anybody, but since surgery..I have moments, quite a bit actually where I feel borderline retarded.
But than you may go to the next guy/girl who feels like a million dollars after surgery. I think it's hard to really answer your question.