Aumann agreement theorem
True, outside of mathematics most problems have more than one solution. One exception is jigsaw puzzles, which have only one solution, although there are many different ways to reach it.
It also depends on what you mean by "solution". the solution is also how it's solved, for many of us. the process. If you do the sides first, your experience is different and therefore your solution is in a tangable way, different. If you are going to be literal about a "puzzle" and a solution.
Math problems (usually) have only one solution, but math is an artificial construction we invented to define and describe our world. teh solution is actually contained within the definitions.
I know next to nothing about chaos theory, other than the new agey take, but it strikes me that theory would prove me wrong, if it were proven right, cause then there really is only one way everything can be. I think....