Some of us have the same experience with real life problems. It's fun to work on the problems for a little bit, but then the realization hits that it's arbitrary and it all seems pointless.
For some, there is no deeper meaning to be found.
At that point, you can either choose to sit and do nothing (die), or engage and play (live). Since the choice is meaningless anyway, you might as well follow the path that gives you happiness. Life is simply more pleasant that way. Along this road lies the pleasure of enjoying things as you did when you were a child, while also uncovering and solving new mysteries (as you did as a child).
For some, there is no deeper meaning to be found.
At that point, you can either choose to sit and do nothing (die), or engage and play (live). Since the choice is meaningless anyway, you might as well follow the path that gives you happiness. Life is simply more pleasant that way. Along this road lies the pleasure of enjoying things as you did when you were a child, while also uncovering and solving new mysteries (as you did as a child).