I've finally become comfortable using menstrual cups, but it took me a long time. I'd never put anything inside me before and I was really scared (I came from a sex-negative family, and despite my father being a doctor, they were both convinced that tampons were only for "loose women"). I honestly didn't even know menstrual cups existed before college.
I went to a very hippy-dippy college and I actually learned about menstrual cups through ecofeminism, which was really big on our campus. Everyone in our school's feminist club seemed to use one, and I wanted to transition, but I never even used a tampon before, and I wasn't even really sexually active. The thing I was most scared of was removing it. I was scared I'd never be able to break the seal!
I tried with the DivaCup in 2010, but the suction bit was really scary, so I stopped and tried again with Softcup (pilfered a lot from the BUST Craftacular, where Instead was a fiscal sponsor). The Softcup kept popping out, though, and I thought I was cursed to be one of the few women who Never Got It.
After college, I finally tried with tampons with my sister's help. At first I used tampons with plastic applicators, but then I transitioned to o.b., and that honestly really made me feel the most comfortable with my anatomy, plus I found it a little easier to use than the applicator tampons. I kept reading on forums too (including the LJ community, menstrual_cups), and I bought a Lunette cup because I lost my Diva in the move. I found Lunette way easier to insert and to create the seal, and now here we are. I don't think my seals are completely perfect yet, but it's made me realize I don't bleed as much as I think I do, and in the future I think it'll come in handy for swimming, doing yoga inversions, etc. And now I'm trying to convert all my friends!