It's true that post-mortems with GMs can be real eye-openers. I've lost track of the number of games I've played when it felt as though I had guessed or at least anticipated 90% of their moves, etc, whatever the result might have been - but then they show you afterwards the variations they had considered during the game, which did not come close to appearing on the board, and then you see the real difference.
When I was a teenager I played Smyslov at Lloyds Bank and was too shy to ask for a post-mortem! Oh dear ... (I didn't even ASK!)
