There is theory, which can be understood as a (intellectual) model of how something works, and then there is practice in which theory can be applied to get results. Another word for practice is work, in the case that the thing being practiced is applied towards some end with effects in the real world—e.g. you can practice baking pizzas through your work of making pizzas to please customers.

The Nerd's Folly

The nerd has theory but fails in practice. For instance, a nerd may have lots of knowledge about health/fitness things in the sense of textbook learning. Failure to apply this knowledge in practice gives this person the appearance of a hypocrite—if they are soooooo smart, then why can they not apply their theory for results?

Babbling on about theory before confirming it experientially by putting it into practice can be very bad because it can turn people away from good theory as they look first at the character and results its proponents put forth.

Nerds ought to inspect themselves and be humble. If they're smarter than everyone about XYZ software, can they direct a software project to produce something better than the existing solutions? Many people can and do quietly labor in this way, doing quality work not through first announcing their theory but by gradually refining their methods through tireless toil.

Working Knowledge

Knowledge should be useful for some kind of work; that which isn't can be called "idle", "speculative", etc. ¹

Work can be done on lots of things. There is work on developing ourselves. ² Also, there is work on the external world for the purpose of making money, getting food, moving from place to place, etc.

When theory is in excess or in error, bad theory should be refuted and discarded and good theory should be retained and put to practice. More theory (not necessarily new theory ³) should be sought out when the the current theoretical resources are insufficient to accomplish the work at hand.