Do you have regrets?

A university did a study with members of the senior community and asked what they regretted most. The majority said more risks and missed opportunities.
I have missed a lot of opportunities and risks in my life. I regret not going to Rome while in Italy, having a closer walk with Jesus, treating my friends and family better, retiring from the Marines, being a better dad and husband, not starting my business sooner when the passion burned in my heart thirty years ago, wanting to step out of the box when I was "too comfortable" and the list goes on.
What will be your biggest regrets?