I masturbated from the time I was in 2nd grade but only externally, and I never used tampons growing up. I didn't have a penetration experience of any kind until college and I think it was a sharpie, paint brush handle, then an over-sized plastic crochet hook. I was disappointed that I couldn't feel anything from the smooth plastic so I bought a really small jelly vibrator. Soon after that I had my first pap smear.
The pap smear was extremely painful for me, but it opened my eyes to the possibilities of my vagina, haha. Haven't had any problems with toy size or insertion since then.