In my foggy memory, mead tasted like very sweet beer, so I assumed some grain would be involved, but perhaps not.

If the flavour comes only from honey (and the process), it'll probably be a lot harder to imitate.

I have friends who've made mead out of skittles

Isn't sugar, water, and yeast basically the ingredients for hard seltzer? Add some flavoring after the fact and I feel like you're having a pretty good time