When does caching actually slow things down, you know, becoming a bottleneck instead of helping performance?

weve all implemented caching to speed things up, right? usually, its a win. but im starting to wonder about the flip side. at what point does managing the cache, dealing with invalidation, and handling cache misses actually start slowing things down more than it helps? especially with highly dynamic data, when is it better to just hit the database directly? curious to hear your war stories.