I assume that you are asking why I decided to become a mechanical engineer. The short answer is that I have always been interested in how things work and why they work. When I was much younger, I liked to take things apart. After graduating from college, I got a job in the Power Generation Industry (an industry that I knew almost nothing about). As I learned about the industry, I became very interested in rotating mechanical equipment (steam and gas turbine-generators) and made a career of working on them and ultimately became a consultant on their operation and maintenance.
Hope this helps,