What is the biggest waste of money you have ever made, and was it worth it?

My biggest waste would probably be vocational school. I took up a pharmacy tech program worth $10,000 while some people I know paid not a dime since they had a program through high school. I am no longer doing anything regarding pharmacy tech nor do I have any plans to, I still owe $7,800. In a way I regret it but if it werent for that, I would have not met my husband nor had the beautiful kids I have now...Anyone else?