This thing is a tree in computer science. It is so fking troublesome and messed with ur brain everytime u tried to code it.
Moreover, it appeared multiple in the National Olympiad in informatics so it becomes more shitty.
Hence, this phrase can be used to describe how messy someone/something is
Daniel: Hey look! the first problem of NOI 2007 day 2 is a splay tree problem.
Brian: WTF!!! I'm definitely not doing that