The stuff he considers complex is mostly complex because it handles a lot of corner cases, or else it has back compatibility constraints he will be dealing with as well.
Good luck to him though. Doing stuff for fun is the best!
And yes, complex stuff sometimes tries to handle "everyone's use case" but if you can limit yourself to 95% of use cases, your code suddenly become a lot simpler. The backward compatibility consideration holds true as well.
For example, I have been creating an Async Library (plus a few other things like the FileSystemWatcher etc.) that cover a good portion of what is done in libuv. Of course libuv code handles A TON more of edge cases and has a lot of compatibility constraints, but with a lot less code I can provide enough functionality to satisfy a lot of use cases. Not all use cases, but a lot of use cases.
Thanks for the good luck! I am definitively doing it just for fun :)