I'm just about 34 now and bought my first Viper at 33 and have waited 20 years to get one and finally felt as if I had done enough professionally to earn it and reward myself with my childhood dream car. Have owned many other sports cars before the Viper including (from most recent to oldest) 2008 Audi TT, 2002 Audi TT, 2005 Nissan 350Z, Acura RSX, and 1994 Chevy Camaro (first car I ever bought at age 21), but all were a compromise of some sort no matter how much I loved them. My first car at 17 years old was actually not mine, as i had to beg to use my parents' 1990 Oldsmobile Cutlass Cierra that didn't have power anything, and smelled like musty farts most of the time thanks to a friend who sharted himself in the passenger seat one time! I would literally pick girls up for dates and they would scowl at the car and ask me if it was SERIOUSLY my car. haha! If I had owned a Viper in my early 20's, I probably would not be alive today as I was not as careful or mature as I am now, however, I also could not afford one back then, nor could I justify such a purchase even when I could afford it. I waited to buy it until it felt like I had achieved enough professionally to reward myself with one of my lifelong dream cars, the Viper.
I would never be rude to anyone, especially not a fellow car/Viper guy, but I'm sure that the first thing that would go through even my non-judgemental mind if I met someone who bought a Viper at age 21 (not knowing the year or purchase price or the person's situation) is that they were a spoiled rich kid who's parents essentially bought them the car either directly or indirectly, or that they didn't earn it since they are likely straight out of college. No offense meant as I'm sure we would get along great if I met you, but I'm sure that's the same thing those other guys were thinking too and they probably couldn't hold back their feelings.
It is tough to be so young and own such a high end rare exotic like a Viper without getting a bunch of negative reactions from people who will rush to make negative assumptions about you. Unfortunately you will have to learn to roll with the punches until you are a bit older, or you are going to get annoyed by people's negative comments and reactions to you driving a Viper for quite a few years.