RTFM
Most software comes with a manual which no one reads. Instead, humans have a tendency to skip the manual, play with the software, and then proceed to go onto online forums or their friends and ask how they can do anything.
Manuals are generally written by software companies to teach users how to use their software. Manuals written by the software companies are generally very well written because it is in their best interests to have customers who understand their software well.
People often asked me how I know the software which I use so well. Because I read the fucking friendly manual (RTFM). When I was little, my mom told me that in order for me to use my dad’s brand new PC, I have to first read the MSDOS 3.3 manual, so I read it cover to cover. After I finished with the User Guide and proceeded to use the PC, my mom reminded me that the manual comes in two volumes. So I read the Reference cover to cover also. I still remember some command parameters (aka flags) til this day. (Edit 2023: I no longer remember DOS commands anymore because I rarely use PCs these days. I do remember Linux commands that I learned way back in the 90s though.)
Similarly, when I started using Photoshop 3.0, I read Adobe’s manual cover to cover. The same applies for Illustrator, Ableton Live, After Effects, Premiere Pro. For software which does not comes with manuals, I read O’Reilly references and cookbooks cover to cover: Java, JavaScript, Python, … I read all the manuals for Canon EOS 10D, 7D, 580EX, … I read all the manuals for everything which comes with the manual.
RTFM. This is the only way to learn everything technical. And if it’s not technical but it has a manual, read it anyway.