Mission Possible

So I’m sitting here in my home on a quiet Saturday morning before anyone else has woken up thinking about things I want to accomplish in my lifetime. Here are a few randomly selected items on my list:

Make a complete list of everything I want to accomplish in my lifetime (so I will know when to stop).
Find a polynomial time algorithm that solves the Travelling Salesman Problem.
Figure out how to rearrange the molecules of our planet into a vessel capable of safely transporting intelligent life out of the solar system before the sun explodes.
Get my daughters to clean their rooms before the sun explodes.

Obviously one of these problems is truly impossible.

So why do I even bother with a list like this in the first place? Or how about I set the bar a bit lower and make my list “stay alive”? The obvious answer is that I like puzzles.

Well, at least it is obvious to me. What makes a good puzzle anyway?