Feature Request for Google Reader

Google is a great company and has some great online applications that are really well done.

Google Reader is one of them and is my default reader for my rss feeds.

But why does it not have a simple search function for searching through read posts in your feeds?  I hate having to try to find a particular post and have to hunt for it.

Does Google not know how to do search?

Update:  Here's a hack to search your feeds using Google Co-op.