One time I heard that you should replace your entire spice rack every 6 months so that everything maintains flavor/freshness and I thought "pfft I'm not doing that. What a waste of money!"
Well, this weekend, I started to go through my spices to clear some out and replace a few and just about every single one of them had expired like 2 or 3 years ago! Gross! Maybe I need to find a happy medium and re-place/replenish every year or so.