As a former passive income hustler turned startup guy - this is so true. What's most important is to be comfortable with what you do regardless of others opinions. That's the one thing I could do without in start up land. The prosthelytizing.
Too true. The trouble is not enough people are trying to address the underlying problem - the lack of education in our public schools needed to become a desperately desired rails programmer! Computer programming should count as learning another language!
Interdisciplinary projects have a lot of potential to be challenging and rewarding. Bioinformatics, Computational Neuroscience, etc. - these are your phd jobs. Another cross disciplinary project is entrepreneurship (you have to do everything - marketing, finance, product development, etc.) and this doesn't require a phd.