Knowledge as it Should Be (3.5e Variant Rule)

The Problem
The Knowledge skill is the cornerstone of the learned character who knows a lot about the world around him. Unfortunately, it comes with the gaping flaw that if you roll poorly, your character has had an utter brain fart and doesn't know jack-squat about it - even if his background and experiences dictate that he absolutely, positively should know it. And you can't retry a Knowledge check. This is a problem with a very, very simple solution.

The Solution
Your Knowledge check result is not what you know, period, but what you can remember in the heat of a moment - being asked a question or confronted with a threat - off the top of your head, especially when your sources (textbooks, confidants, notes, etc.) are unavailable, you're not allowed to resort to them, or you don't have time to look up the information. This lets your character know stuff that he ought to know - he just might not be able to come up with that information on immediate demand, which is a limitation that real people have, too. However, given time, he might be able to recall it. A minute after your first Knowledge check, if your character's attention wasn't otherwise occupied (such as by combat), he can be assumed to have been thinking about the subject, and he can retry the Knowledge check with a +1 bonus. Multiple retries are allowed as long as there is at least a 1-minute interval between retries and the character is not significantly distracted at any point. Multiple retries have a cumulative bonus, but the bonus for spending extra time to think on a subject is capped at ¼ your ranks in Knowledge, rounded up. If you have the "Lol Media" feat or Time to Think skill trick, the bonus is instead capped at ⅓ your ranks in Knowledge, rounded up. If you have both "Lol Media" and Time to Think, the bonus is capped at ½ your ranks in Knowledge, rounded up. The usual restrictions and extra benefits of these abilities still apply.