How did you learn photoshop???

I learned Photoshop on my own by reading every tutorial with the word "Dummies" in it. I was probably the last licensed artist in the civilized world to go digital, kicking and screaming all the way. And now I can't imagine going back. I mean the money I save on art supplies! It's great. I also got a digital camera, learned that, and started a sideline as a stock photographer thanks to Photoshop. I don't think any one person could live long enough to discover all that Photoshop can do.

Adobe still produces Classroom in a Book. It's a good starting guide to teach you the right methods in Photoshop.

Playing around can get you so far, but can also lead to bad habits or unexpected outcomes.

LinkedIn Learning (formerly lynda.com) and Youtube channels like Photoshop Training Channel are good options as well for visual learning.

I got PS for work, when we went digital. Bought some books, but mainly just played around with it. I did take a couple courses. One I didn't learn much. The other was a seminar by Bert Monroy. He showed what PS could do outside of photo editing. I used to go to Photoshop World, when I company picked up the bill. Learned some things there. Basically just picking up tips from anywhere I can, and lot of playing around it it.

Treat Photoshop like a Toy.  I play with it like I 'm in a sandbox.  I played with all ist toys. Features, script, action, filters  tickling all of its buttons, in any menu I found and slid the sliders observe what happens. I read actions I download to see how other were playing with my toy. Read Photoshop script code of adobe and others. I read this forum and ask questions and receive help. Its an on going process it never ends. I do not think it is possible to know all of Photoshop.  My mind does not have the required capacity or knowledge to understand all that happens.  I only remember and use some of it shortcuts. Only know where some of the bugs are and some of the features the have issued.  You will never know Photoshop Adobe keeps changing it. You can only be an expert user and deal with what is good, poor and work around the bugs.

When I first started learning Photoshop (before it even had layers), it came with a 1-1/2 inch thick printed user guide in the box. I sat down and read that enitre thing. Of course I didn't retain all of that info, but when I came across a problem I needed to solve, I could at least remeber that the book had a solution, so I'd go back to the and look it up. 

Later, I went to some seminars, and traded techinques with my co-workers.