Well, I understand that not everyone goes to school. I am self taught.
I read every book I could get my hands on, on posing, lighting, composure, exposure etc...went to seminars whenever they were available, joined photography groups (real life...it's important to have "hands on" experience & real life feedback, teaching & support), spent time on "strobist" (even though I didn't end up going that way with lighting, it was a great resource). Searched all over the web for the styles of photography I liked then found out how to do them. Attended web seminars. Practiced on anyone and everyone who would let me. Posted photos here. Asked questions here. And I never expected people to tell me I was wonderful. I listened to criticism.
I learned photoshop (it's too important in this day and age, to not know how to do) the same way. There could be a whole different thread on being professional with photoshop and mangling a photo with it but I won't go there. 
After (<----this being key) I was very comfortable with photography as a whole (see everything I mentioned above) etc...I tried to get an "internship/2nd shooter gig" around here but no one was taking on assistants. So I started with advertising myself and doing portraits & the $500 wedding thing. I made sure my contract stated I was a novice to WEDDINGS and that they clearly knew they weren't promised anything. I did a couple of weddings that way and then my business grew and so did my price market...I also went to every public event I could find and photographed everything. I practiced technique there (because weddings are so often like photojournalism that public events are a great venue for practicing). If you miss a shot, it's gone...events are fast moving etc...just like weddings. Then I would go home and process the shots, just like if I had to do a wedding.
So it is possible to start from scratch and work your way up. But instead of going to classes and people handing you things to learn, you have to dig. It doesn't excuse not learning...it means you have to work harder to find out what you are supposed to learn...and learn it.
Most importantly, you have to be "teachable". Meaning if your peers are saying (and I'm not talking about trolls...just peers...it's pretty easy to weed out the difference in a forum like this) "this is a major weakness in your photography right now...work on it" then you have to be willing to say "okay" and do it. Because in lieu of paid teachers...you've got mentors. That's what I see is missing here. When people are willing to say "this is not up to snuff" then offended pride rears it's head and ready or not, the rookie plows forward.
Photography right now is a tough business to break into, because the market is flooded. So in order to really succeed you have to be the best in so many areas. I'm just touching on photography here (not business or marketing)...but in order to be the best, you have to work at it.