Ath'kethin
Elder Thing
What you're describing is pretty much what I landed on. IME it's easier/better to assume characters have been practicing, studying, or researching stuff in their downtime, and gaining a level more or less just marks the point where they can do [skill X] consistently enough for it to be reliable.Yeah this issue actually makes me wonder if it ought to be done flashback style, where you figure out, taking turns, where you got your new toys. Definitely soemthing to consider.
Now, that only applies to class abilities, feats, and stuff like that I'm all for setting up a quest if a player wants a specific magic item, or incorporating that quest into another ongoing adventure, or what have you.
I pretty much just decided not to worry about it.