Hours? It's more like about one minute --- that's how long it takes to do lesson one of vimtutor, which tells you how to save and quit, move the cursor, and insert and delete text. Going all the way to the end of vimtutor would probably take about 15 to 20 minutes, and assuming you remembered it all would make you pretty effective (I've been using vim for years and there's basic stuff in there I've never used; skimming it just now I kept going 'huh, I did not know that').

I will admit that the vi learning curve can be stupidly steep in places, but right down at the novice end it's not bad at all.