because after adventuring for a bit you'll just end up picking up some things, it'd probably be statistically impossible NOT to, from watching and listening to your fellow party members, from chats with shopkeepers and bartenders, from practical experience, i'm sure you have an amount of bits of stray knowledge rattling around in your head that aren't related to whatever you do for a living that you never went out of your way to specifically pick up, just things you've learned because one day you read it in a book or a family member needed your help as a second pair of hands.
i'm not saying they should be as competent in these areas as their own area of expertise (i noticed you changed that bit of phrasing), i'm saying that after a few adventures they shouldn't be as incompetent in these areas as the day they started.
