Graphic design, music production, clothing, what-have-you; You can’t become knowledgeable in any discipline strictly by “reading the book”. You have to get your hands dirty and mess with all the settings!
I know my way around Photoshop and other software, but I don’t know EVERYTHING. But most of my knowledge comes from just fiddling with all the settings I can find. Because, honestly, I don’t know what all of these icons and tools do and what affects they have because I’ve never really had to use them, but what better way to grow your knowledge than to get to know what these things do?
Messing around with things you don’t know about is THE BEST WAY to learn and grow because it’s not that I know a lot about whatever I am doing, I just know what NOT to do! I’ll mess with anything and everything and yeah, I get myself into trouble sometimes, but it’s when I get myself out of trouble that I truly understand the purpose and effect of of that feature. And from that point on, me having prior experience with that feature, function, filter or button increases my abilities — not a book.
Now, go fiddle with somethin!