Anything you don't value will definitely be of a great value to another person who will use it judiciously, wisely to achieve more positive results from it.
You are together and then you part ways, next thing that comes to your memory was "How I wish I knew you more"
When you were together what where you thinking that made you not to take chances....... Hmmmm
Please, I need more expansiation on this statement.

Lol

I think this is the case of the person changing, you prolly didn't know much or the person changed from the 'good' he/she used to portray.

From your first statement, i think you 've answered your question...