When will I know it's right?

I find it so interesting when I look back at old pictures, cards or letters and see how much has changed. I refer mostly to old relationships. Today I was cleaning out my desk and I came across a letter I had written my ex but never gave to him. As I read it I was wondering when I ever felt those feelings or what drugs I was on...lol.

Not to say I didn't care or love him but I can't ever imagine feelings those things now and believing the things I wrote. Isn't it funny how you can think you are so in love and then a few years later you don't remember how you could have loved that person? It actually scares me to be honest, I was so sure then but I was so wrong.

When will I ever be able to trust how I feel and know that it is the right decision?