We've experienced remorse with a couple of our house purchases.
First one was fairly rural with only two near(ish) detached neighbours. We didn't know the area as it was a long distance move and although we'd tried to speak to the neighbours on one of our two visits to the property, we'd been unlucky.
On moving in day we went to introduce ourselves to the closest one. They were an older couple (early seventies?), but he was the only one home at the time. He seemed a bit unfriendly, but we assumed shy/unused to strangers. Almost immediately he launched into a tirade about the other - further from us - neighbour, who had recently started hosting functions at their huge property. He wanted us to support him in his attempts to get these stopped and tbh, came across as a completely obsessed nutter.
We went 'home' with me in tears (it was a repossession that had been trashed, so needed everything done, so not remotely homely) and determined to put the house straight into auction to get shot of it (but we stuck it out, fully renovated and made a big profit when we sold).
The first function was a wedding several months later - the only noise we really heard was a harpist playing in the grounds. Apparently, Mr Mad went up to the boundary hedge closest to where she was playing and poked a noisy power tool though the foliage to disturb her!
They were only allowed to hold four functions per year and when covid happened they stopped/sold up. In almost seven years we never met Mrs Mad and wondered if he'd bumped her off!
The other house we immediately regretted was another with a nutjob neighbour. There was a (admittedly huge) specimen cyprus conifer on our side boundary and at our first meeting he asked when we'd be chopping it down, because he had to hoover the pipe needles from his drive! We liked the privacy it afforded, so said we had no plans to remove the tree, at which point he became all shouty and irate.
A matter of days later we came home to find he'd had a tree surgeon cut it in half...vertically so that no branches overhung the boundary, but as the tree was some distance inside our land they'd cut right back to the trunk - it looked bloody awful. We'd have been perfectly happy to trim back the offending branches if he'd asked nicely without becoming threatening. We sold that house after three years to move closer to family, by which point the nasty neighbour had died (probably combusted in anger!)