I don’t know much about Søren Kierkegaard, except that he was Danish and is widely considered to be the first existentialist philosopher. I learnt those facts many years ago when I did a Masters in French Thought and finished the year only marginally wiser than I was at the beginning. However, I’ve recently discovered that he did say the following, which I consider to be well and truly on the button:

Life can only be understood backwards, but it must be lived forwards.