probably because he adopted the number 86 in his freshman year of high school, so his first love was either in middle school or high school. probably how they came to that conclusion. They said he had been sporting it for awhile, so perhaps the press knows that he got in high school.
I mean I understand it kinda make sense but still there's a hole in it that means ian first love happened on period before ian got his jersey number so it could be on middle school, elementary school, or when he was in kindergarten even, the possibility is endless~
that's why the woman said ian has 12,000 girlfriends, aka people talking about who and when he would've gotten with certain girls. the comment itself just seemed more trustworthy because of other people backing it up in the replies + fit within the respective time period (before high school when he got the number). All of it is just meant to come off as a rumor that someone is pushing as a fact (with some evidence to boot), something that often happens to celebrities east and west.
But ian never mention what year how the comment concluded its on middle school days