Partap, what I like about mechanical engineering is that there is always something new to learn about or a new creative way to solve a problem. I have moved between consumer electronic and medical devices. As an young engineer, I learned about the product development process and working with the factories to make my designs reliably in mass production. Later, I was given challenges that I applied engineering principles and concepts to resolve thermal issues using radiation heat transfer and free convection. In medical, I worked with PhDs to solve issues in tissue optics. Yes, tissue optics is a real thing.
After a while, I was looking for new challenges and incorporated people management into my skill set with positions that included project management and eventually people management.
The main thing is that I have continued to learn and grow throughout my career, always using critical thinking.