I lived in Japan for close to 20 years and, after 10 years of living in Australia, there are still many Japanese words that are part of my mental language — you may never hear me say them, but they are the ones my mind goes for to describe certain things.
My favourite is probably mendokusai. Unlike some others, like fuinki or natsukashii, which don’t really have straight English equivalents, it translates pretty easily as What a bother! or It’s a hassle.
But there’s something about mendokusai that I love and that makes me prefer it. I think it’s the hard consonant sounds that do it for me — and that I can draw it out into three distinct parts: men doku sai. That doku means poison also helps add the feeling that something is such a hassle that it is toxic.