Actually if it weren't for Rarity I would still say negative things about myself too and give up on my life goals. But Rarity being so passionate with her fashion being her passion (to quote good old Pinkie Pie in Putting Your Hoof Down) and full of integrity but also struggling with innermost conflicts I decided to continue with what I want. Rarity is the most 3D demnisonal out of the Mane Six for me and most interesting. She struggles with many internal conflicts with her vain and everything but also has a pure polished heart of gold.
Honestly Rarity is who I want to be like a little bit more. So when I was 11 and 12 I saw her (and Twilight) as a role model for me at the time (yeah, I've been in the fandom when I was 11. I was a pretty young Pegasister/girl Brony XD.)
She's passionateofm couse, generous we all know, is more social and extroverted (not nearly as much as Pinkie though hehehe) than I could ever be being introverted, has class we all love her for, does excellent in social events, has a creative mind, is pretty inspirational, is a nicer sister than I am to my own little sister and my big brother, is a rare pretty gem in general, can be pretty humorous and witty, and despite bien generous she learned that sometimes others can take advantage of you but that doesn't mean you should stop being generous which is a good lesson in my opinion, etc.
I could go on and on why Rarity influenced me a lot when I was young and how much of a great role model for 11-12 year old me. I still kinda wish I was more like her.
She is a hidden gem afterall.