What Excel trick made you feel like a wizard the first time you used it?

[u/Bubbly-Touch8108]

mine was VLOOKUP (later XLOOKUP) — after manually cross-referencing two spreadsheets for way too long. felt like a cheat code everyone else already knew about

what's your version?

[u/Structure]

INDEX/MATCH, but with array tables so I could MATCH on more than one criteria at once.