Mastering a programming language is not enough to write efficient code.
Programmers often try to squeeze a programming language as much as they can in order to achieve the best performance, without realizing that the solution could be found in a more efficient algorithm or data structure.
The talk is meant to inspire you to learn more about algorithm design by demonstrating, with real world examples, how a properly designed algorithm may drastically increase the efficiency of your code, regardless of the programming language you are using.