I can't think of a specific moment where I suddenly knew I would be happy and satisfied in a career as an engineer. Engineering involves exploring a problem and using your background and experience to develop one or more solutions. You then apply a systematic process using engineering methods to solve the problem in a practical and cost-effective manner. So if you can take on a challenge and enjoy doing detailed analytical work to solve that problem, engineering can be a personally rewarding career. I am a Civil Engineer and I have always found great satisfaction in working on projects that directly benefit communities and the environment.
I hope this helps, Pete Sturtevant, Pete Sturtevant, PE