Mmm waxasay circulates online as a short, shareable reaction clip with no clear confirmed source, which is part of why it works in so many contexts. The nonsense phrasing is easy to quote, easy to search by its distinctive spelling, and short enough to drop into edits without explanation. It has spread through soundboards and chat sharing where users collect brief voice noises for jokes, confusion, and random humor. Its continued use comes from that flexibility, as it can signal thinking, tasting, or total bewilderment.