"Specialization is for insects", writes Robert Heinlein in Time Enough for Love; a sci-fi novel that I haven't read, but I've thought about that quote for some time now.
I cannot compute the thought of doing one thing, or being limited to one title for the majority of my time on Earth, but I understand why it occurs.
Most people find a job, or start their own business, and achieve a certain lifestyle that serves as good enough. It turns into a trap, and starting over to achieve something different begins to look like an impossibility.
History favours those with the ability to start over; those that take on different challenges and aren't afraid to fail.
Bruce Lee: Martial artist, instructor, philosopher..
Winston Churchill: Writer, military strategist, politician..
My father: Engineer, statesman, writer..