The Bridges of Madison County/廊桥遗梦

Honestly, I understand the point of the movie: to find the true love of yourself, because "this kind of certainty comes but just once in a lifetime." One should balance his/her love emotion and something else such as responsibility, which is true but it is not an excuse to barrier one's pursue to his/her happiness.

However, I know the point of the movie, but my point is: how can one make sure that this is a "love once in a lifetime"? It is very difficult. I am not afraid of change, I am not afraid of strangers, all what I am afraid of is how to make sure this is my love once in my lifetime based on my limited knowledge to my life?

Quotes:
Robert Kincaid: This kind of certainty comes but just once in a lifetime.

Robert Kincaid: I don't want to need you, 'cause I can't have you.

Robert: The old dreams were good dreams; they didn't work out, but glad I had them.

Francesca: Robert, please. You don't understand, no-one does. When a woman makes the choice to marry, to have children; in one way her life begins but in another way it stops. You build a life of details. You become a mother, a wife and you stop and stay steady so that your children can move. And when they leave they take your life of details with them. And then you're expected move again only you don't remember what moves you because no-one has asked in so long. Not even yourself. You never in your life think that love like this can happen to you.
Robert Kincaid: But now that you have it...
Francesca: I want to keep it forever. I want to love you the way I do now the rest of my life. Don't you understand... we'll lose it if we leave. I can't make an entire life disappear to start a new one. All I can do is try to hold onto to both. Help me. Help me not lose loving you.

Performance impression:
Cast: Clint Eastwood, Meryl Streep