...you don't remember what you were doing 6 months ago? I'm sorry, that's still not a good excuse. Maybe you don't remember every tiny facet but hopefully you'd have a general idea. And above all that, if you're a senior dev then you'd understand that "this code is unfamiliar" does NOT mean "this code is bad."

I mean really, "this code is unfamiliar therefore it's messy therefore we should rewrite it" is a flaming red flag. Chesterton's fence, people!