"Je suis tombé amoureux comme on s'endort lentement puis d'un seul coup"

Simplified Meaning:

Falling in love can start gradually, like how we feel sleepy bit by bit. At first, you might just like spending time with someone, enjoying their company. Over time, these feelings grow stronger without you really noticing. Then, suddenly, you realize you’re deeply in love, almost like a switch turns on in your heart all at once. It’s similar to how one minute you’re just a little tired, and the next you’re fast asleep without even realizing it. In everyday life, you might meet someone and initially think they are just a good friend, but as you get to know each other better, your feelings intensify. One day, it hits you that you can’t imagine your life without them, illustrating how emotions can quietly build up and then become very clear all at once.