Hi,
@Hugo. How old are you? Sometimes older people have more trouble with brain fog after general anesthesia.
I'm 59 and had general anesthesia March 9 of this year. I'm still experiencing increased brain fog from the anesthesia, but it's much better now. I don't expect it to be permanent, but it's been a problem.
Regardless of your age, I'd suggest doing some brain wave training after the surgery since anesthesia can increase slow wave activity, which can cause spaciness. Transparent Corp. lets you download a subset of their NeuroProgrammer software for free so you can try it out. If you did this, I'd listen some of the Beta and Study Focus sessions, which entrain the higher waves associated with attention.
https://transparentcorp.com/products/np/