Yes in a way. A lot of my hunting is at old sites in the patch or iron and often times the site is fairly well detected and I'm trying to squeeze out more signals. Sometimes I get get in the zone with good concentration and keep finding something non iron, but if I lose focus the site seems to get a whole lot less productive. It's hard to put in words but would be a step or two above you because I've been swinging the same detector for a long time, and hunting these type of sites just as long. I'm definitely not talking about easy targets because the examples of this that come to mind were on hunts all my friends left the patch to go walking.
You'll probably keep learning little things for quite a while and eventually there won't be good and bad days in the way you're having them now, there will be normal detecting and the good and bad will depend on the site and maybe how lucky you are.
PS: Sounds can change depending on how much moisture is in the ground so if you hunt a dry sunny day and have the good day, and then have the bad one on a wet day, backing off your sense might be the answer. But even if you make no changes you'll will get used to it.
