Unreasonable ineffectiveness of mathematics

Unreasonable ineffectiveness of mathematics means that sometimes math does not work as well as we might expect - even though it looks like it should. For example, some math problems are very hard to solve or take a very long time to solve even though they look like they should be simple and easy. Sometimes, math doesn't have the answer we wanted, even though it "should"! It's like math is not working as well as it should, and that's why it's called the "unreasonable ineffectiveness of mathematics".