Is it normal that i don't wanna be what my family expect from me?

I'm almost 29. We've always had businesses in my family since a couple generations. We're not rich or millionaire, but we've always had small successful businesses. So, I went to college to study Administration and Accounting, and I also have taken many classes on those topics as well as Management, Human Resources and the like... To fulfill my family wishes of one day, ruling the family business along with my brothers (who have their own lives, and I don't think they will rule the business as well as they may think). But to be honest, I don't want to. I have worked in several Administration jobs, and I think I've failed (despite I used to think I truly loved Admin. and Accounting). I don't wanna rule our family business, but I feel I have a huge weight on my shoulders, to be responsible, to man up and just to carry on, even if I feel I'm wasting my time studying, taking classes and preparing myself for a job that will likely lock me up in an office, just to make me feel miserable. I do feel all my family is counting on me to be "THE" man of the house and lead the business. Actually, I found out I love motors, car mechanics, bikes (even bikers lol)... The sole idea of getting my hands dirty with oil excites me lol, I now it may sound weird, but, I think I found something I honestly like for the very first time in my life... and I'd like to give it a serious try. Just not sure what to do, or how to explain it to my family. Am I normal?