I made the mistake of clicking the Date and Time column in the event log. Now, whenever I open that log, it takes like 10 seconds for it to sort all entries.
This is highly annoying, especially since the entries are sorted by date and time by default. But now I always have to wait for the delay.
I know I can just restart the MMC. But this is my initial Server Manager instance, and I just expanded all the branches I like.