Spoken like a strong independent member of the first world who don't need no harvests and caravans.
I disagree. I don't think planning ahead is strictly a "first world" consideration. Actually it's more important in an agrarian society, not less, for precisely the reason you're suggesting. Sure if you wait until the food runs out before doing anything about it then it's probably too late. But whether you get it from Safeway, a medieval farmer's market, or you grow it yourself, the trick is to stock enough to last until the next harvest or shopping trip or raid.
