I heard this quote a long time ago at university. The French department boasted the French lecturer's answer to Sean Connery. We all took papers Pierre Daprini taught. Whenever he wanted to remember something, like an extra photocopy or to look something up later, he would extract his handkerchief from his pocket with a flourish, ceremoniously tie a knot in it, and return it to his pocket saying "comme ça je ne vais pas oublier", a foolproof way for remembering things apparently. Pierre Daprini introduced me to Modiano's novels, which made a lasting impression on me. But more notably he used Lamartine's quote to illustrate some literary point which, having not tied a knot in my handkerchief, has now escaped me. I liked the sound of this quote and the imagery it conjures up, long before I could have ever understood how the feelings expressed through these words might feel from the inside.
Et voilà. I get it.