I remember when I was like 13, I had to go to summer camp and I was so terrified, because they force you to swim and I knew I'd get my period while there. On top of that, I didn't know how to wear a tampon. I'd tried a few times before and it just never went in. I wasn't sure where to even put it exactly... and would push until it hurt, then I didn't want to accidentally burst through my urethra or something so I'd be afraid to push more. I'd just gotten my period (at the same camp, another story) the year before and that memory of having to tell strangers (I was extremely shy when I was little) plus the horror itself of having blood come out of me sent me panicking. I was soo upset, it was literally the most stressful thing that's ever occurred in my life. For some reason I felt like it was such a huge deal. I was too embarrassed to tell the counsellors that I couldn't swim because I was on my period, but I couldn't ignore them because they'll literally push you into the water if you don't go swimming. So for a year between the two summers that problem haunted me. Every so often I'd take time to try to put a tampon in, but it was always the same problem. I looked up diagrams, I looked it up online, and the instructions were always the same, to 'just push and it should slide right in,' never going beyond that. There'd usually be a diagram but I couldn't really correlate it to myself. So I ended up not doing anything about it, and sitting on the dock, trying to pretend I wasn't hot in 100+ degrees(f) weather while everyone else was swimming. That was torture. Then since I didn't have to go to camp anymore I forgot about it and stuck to pads.
Worse, until I had sex I always kinda thought there might be something wrong with me. Why was I the only one who had these tampon problems? Why did nothing come up when I searched for it? So I kinda had the fear in the back of my mind until a couple years ago that there was literally something wrong with me.
It wasn't until like a year after I had sex for the first time, only a few months ago actually, that it occurred to me that I could probably wear tampons now. And they are FUCKING AMAZING! And actual sex was easier because, well for one thing he knew where to put it due to porn, and I think with the actual thing it's a lot more obvious even to the girl, because it's what's actually supposed to go in.