I saw you. I fell in love. A bit of a cliche, but such is life.
Only I didn't fell in love when I saw you. It was gradual. In terms of absence. One day, I suddenly noticed you were not there (that is, I was able to distinguish how empty the world was without you in it).
This arrow flew a long time, which only means that it hit with grater strength.
You see, this is not love on a whim. When I see you I don't think "I fell", rather I flap my arms, taste the fear, and think "Why the hell I don't stop falling?".