Weirdly, farts and poop were the smell I lost the LONGEST after covid. I never even realized how complex those scents were until they graaaaaadually came back, note by note, over a period of 2+ years. I experienced a big leap in recovery of these scents after my 1st booster vaccine somehow, and another big leap after doing hormone shots for egg freezing, of all things (then again, estrogen seems to be critical in developing sense of smell in utero). But that was well over 1 to 1.5 years post-infection. That said, recovery took so long that I'm still not convinced it's a complete recovery; I began to forget aspects of those smells.

So, so, strange!