So basically, everyone who took private pictures of their high school sweetheart back in the day and never bothered to delete them after turning eighteen is in possession of child pornography?
Even BEFORE you turn 18. There are cases of <18 yo kids being tried as adults for 'possessing', 'producing' or 'distributing' child pornography. Even the girl who takes the pictures of herself is not safe from this sort of legal system madness.