I think, at least, one time in our lives we doubt the decisions and choices we've made, and we are scared of what the future holds. For instance, who we will marry, and once you find that person, having that trust in them, and hoping and praying that everyday that they will continue to love you and grow old with you.
All I can say is that in the moments when we have to make the tough decisions, even little ones that will influence greater ones, we have to do our best. Always, striving to do our best. When we strive to do our best, even when we're at our worst is when we cannot have any regrets about what we did choose.