When I was younger, I thought that I wouldn't care how I looked, be competitive, or still think I was still 19 once I was "OLD" (meaning 30ish) Here I am, 46 next month, more competitive then ever, still thinking my body is only 19 and still kind-of caring how I look (although my daughter will tell you my clothes never match and I don't really care).
Jiu jitsu is an individual journey, everyone has their own reasons for training, their own goals and one should not judge another's journey. As much as I stress out about tournaments, I feel a deep need to challenge myself. This is part of MY jiu jitsu journey.
The past couple of years, the biggest challenge for me has been getting in enough training to feel like I properly prepared to compete. Next month I am competing at IBJJF Worlds, there is no "Master" division in this tournament, so I will not only be competing with young, athletic women, I will be going the full 7 minutes in each match. Getting prepared means boosting my cardio, dropping a few pounds, training more and getting mentally prepared. All of which has gotten harder as I get older. My recovery time is longer, making it hard to train so many days in a row (especially hard training) losing weight is tougher, I have been on a diet for 2 months and I have lost 1lb (good thing I only need to lose 3) and between working full time, teaching kids & women's BJJ and helping to run the school, getting my head wrapped around "competition mode" is almost impossible! Yet...here I am, not sure what makes me want this so badly but, I do!
I know it sounds like a lot of pressure, stress and wear & tear on the body but, the huge feeling of accomplishment (win or lose) after a tournament is unexplainable!! I highly recommend doing it, at-least once. It is a big accomplishment just stepping out there!
Great book by Gustavo Dantas about competing over 30, some great advice and info: http://bjjover30.com/