If you have ever had the paralyzing thought, what should I work on? Then I have some advice. The most important element to expand your mental capacity is that of language. Now I know what you are thinking. I hated English class, there is no way that I am going to learn language voluntarily!
However, let me walk you through some real examples of this just to prove my point.
Lets look at Calculus as a language. You may think of it as math, but in reality it is a language used to describe the principles and discovery of all the 18th century and beyond concepts on how to perform abstract calculations. During the Einstein years, he and his colleagues added dramatically to this language and the number of discoveries in science and engineering increase exponentially. It is quite obvious when you look at the impact. Just look at the technological innovations that have occurred since Isaac Newton and then look at the progress of engineering since Einstein. When the language was developed, and people started learning it there was an explosion of capability and capacity of our engineering communities.
The same is true with programming languages. When I first started in computer science the very linear languages like COBAL and FORTRAN were still the most popular. There was an up and coming concept of object oriented languages. A further layer of abstraction. Visual Basic, Python for example came out the year after I graduated from high school. However, there was a serious problem going on at this time in systems development. The more complex software being developed required a language that was better at adopting to the needs and requirements of user and developers. The industry was seeing a productivity paradox, where the gains of the computer science that happened in the 50s, 60s, and 70s were no longer happening. So new languages started to form, new models, new ways of abstracting complicated scenarios. When those new object oriented languages started to flourish, so did the application market. Look at where it is today!
This effectively demonstrates that language allows for, encourages, and helps improve complicated thought. The more we can represent ideas, abstraction and concepts with language the more we can make use of them and improve our effectiveness. So when you are wondering what you could work on to improve things, work on language!