I don't mean what you use to chop down your feces, but an object that you realized only your family has and people would raise their eyebrows at. Best if said object has a sole purpose.
Most fitting of these is a tabo. No need for a bidet when water just needs motion. The last time a stranger saw it, they were a child who I had to stop from drinking from it.
A Wii U. The most underrated console of all time because it was only successful enough to make a dozen games on it, yet here I am using it everyday. Hijackers never gonna seize a Wii U.
A hammock. People will always ask me why I have one just lying around in the home, but the truth is at times it's more comfortable than a bed.
A garage. You might be thinking "that's not so bad", that is, until you learn I don't drive (or rather I took lessons but was like nope) and wouldn't put a vehicle in there anyways (add to that I witnessed a house catch on fire because a car caught fire because of badly mass produced batteries). It's mostly for other peoples' vehicles, but it's only been used for a handful of nights. For the majority of the time, it's for storage, especially as it has a second attic.
The biggest poop knife equivalent of all though? A Lemmy account. People discover my Lemmy account from DeviantArt (when they finally decide to look up the username) and they ask "what do you do on there when you got Reddit too". And to them I say this. But seriously, one does not hold the world record for the most websites having signed up for (provable but it takes a long time) and not expand one's horizons.
Of course. The only big regret is a Wii U can't load my Discord server where one may find me and where all are invited (recently added a Lemmy lounge).