Considering that I was a harem protagonist during my elementary to highschool days, also, I was chasing my cousin for roughly 6 years so it should consider that to be falling in love at first sight.
But I also did encounter multiple sessions where I should have fallen for some girls(one where I saved this girl from bullies in some public pool as a kid, another was someone I didn't know but my family thought that I had a crush on her) though I believe that I never really consider them to be love interest and moreso just a curiousitic mindset I had as a kid.
Hell, I never considered any sort of relationship and wanted to satisfy my curiosity of the world at that time. Like, I was a blank state, wanting to understand my reasons for living and relationship was something I never considered at, unlikely though the present time.
Hell, the reason why I was even stalking my own cousin at that time was mainly trying to define the difference in treatment between me and her and not even loving her at all. It was only till I was older did I understand that I was more unto researching the difference between women and men and not even falling in love at all.
But because of my chaotic mind, I interpreted it as a love interest at some point in the past. Not only that, I never really talked to people to understand love was and interpreted it that way at all.
One thing to consider tho, once you began to feel like you want to be together with another person and felt like you don't want to seperate from one another, that should consider falling in love right?