am i wrong for feeling hurt that my boyfriend was more sexually adventurous before me?

my boyfriend and i have been together for a year.
before me, he was really into what he called "the lifestyle." he would bull for couples, had hookups, and was just generally way more sexually adventurous than i ever was.

i'm his first girlfriend, and hes only the third person i've slept with. he has been with way more people than me and has had a lot more experiences.

the thing that bothers me is that it feels like he was willing to do so much more with people before me, but with me he seems a lot more reserved.
i want to be clear that i don't want him doing anything he doesn't want to do. if he has boundaries, i respect that. but it still hurts because sometimes it feels like the women before me got a more exciting version of him.

there are certain things i've expressed interest in, and he says he feels bad doing them with me because he "doesn't like to think of me that way." he says he cares about me too much to view me like that.

i know that sounds like it should be a compliment, but it honestly makes me feel worse sometimes because i start wondering why those things were okay with other people but not with me.

his answer has always been consistent, and he says it's because he sees me differently and doesn't want to treat me that way. but i can't help feeling insecure because from my perspective it feels like he was more sexually open with women he wasn't emotionally attached to.

am i wrong for feeling hurt by this? is this just me comparing myself to his past, or is it understandable to feel weird about your partner having a side of themselves they don't want to share with you?