A few years ago In my appliance repair phase I got called to an old customer on Sat afternoon a doctor his fridge wasn't working, I showed up and couldn't pinpoint the problem within the first couple of minutes, so I stopped said excuse me went outside walked around for a couple of minutes or so, walked back in put my hands on the fridge and got it, said got it, he looked at me and I said I had to leave it for a second or so because I was missing something ahh he says, anyhow fridge is repaired, bill has been presented he says would you like a drink, it was the last call of the day so OK anyhow as he was pouring I asked him did he ever have days where things don't fall into place where he struggled all day and didn't have it easy ( he was at the time chief of surgery at a fairly large hospital) and he said yes not often but there is the occasional day where I struggle and at the end of the day I probably should have just put off the diagnosis until the next day, because then it all falls into place and I wonder why it didn't come to me before. So if he can have days like that and I have days like that every one else can to.
Bill the demon.