I ended up with two problems.
1) I had things in my fridge that were WELL past fresh. (A recent bottle of peanut oil I found had a sell-by date of 2005...) Now I know oil stays fresh longer in the fridge, but that was embarrassing.
2) I threw out things that were probably fine, but I couldn't remember exactly how long they were in the fridge.
SOLUTION? I keep a sharpie in the drawer next to my fridge. EVERY item I put in the fridge now gets the date on it before it goes in. I have much more confidence that the food I am serving is fresh, and above all safe. I'm saving money and space. No more year-old pickles taking up space, and no more throwing something out because it *might* be too old.