fun fact: Boston Museum of Science calls their evening lecture series “SubSpace”, which would be a totally innocuous math term except for the fact that, to make sure you know these lectures are higher-level and not aimed at their usual audience (kids), they chose to subtitle it “SubSpace: Adult Experiences”
worried that thing you put in your art or writing or game or music is too self-indulgent, too self-referential, too niche for anyone but yourself? fear not! you can do whatever you want forever. and you should.