Years ago psychologist Anders Ericsson proposed that to become elite in a field one needed, among other things, approximately 10,000 hours of "deliberate practice". This isn't just putting in one's time (e.g. watching videos and playing bullet chess) but working hard at challenging problems that help develop the relevant skills. Others have gotten rich by popularizing and, in some cases, slightly misrepresenting Ericsson's work, and even apart from that his claims have had their critics.
Ericsson is therefore out with a popular book (why shouldn't he get to cash in on his work?) that reiterates and clarifies his thesis, responds to objections, and offers suggestions about implementing deliberate practice. If you're curious about the topic and/or have followed the debates over the years, you might want to have a look.