I think "arbitrary" gives the wrong flavor here. Math is fundamentally curated. It's easy to create something new, because you get to play with the rules - b

I think "arbitrary" gives the wrong flavor here. Math is fundamentally curated. It's easy to create something new, because you get to play with the rules - but unless it is in some sense deep, effective, and usually elegant [1] it won't stick around. [1] this is a bit acculturated.