For Knowledge - and nearly all other cases where retries are nominally not allowed - my rule is that you can't try again until you improve the modifier on your checks somehow. (I believe this is the standard rule for one or two specific situations, I just apply it more broadly than the Player's Handbook says to.) So if you raise your Intelligence, gain another rank in Knowledge, or get a relevant Feat, you get another crack.
You can cheese this in various ways, for example by casting Guidance or Fox's Cunning to temporarily boost your modifier, giving you another shot. I don't find that objectionable, but your mileage could vary.
You can cheese this in various ways, for example by casting Guidance or Fox's Cunning to temporarily boost your modifier, giving you another shot. I don't find that objectionable, but your mileage could vary.
