Don't let this frighten you but you might be interested.  A few years ago I was having a beer and discussion with an old friend of mine who was one of the top Photoshop lecturers here in the UK.  I said that he must know just about everything in Photoshop.  He amazed me by saying that he thought that nobody knew everything about Photoshop, not even the Adobe guys.  His theory was that the people who work for Adobe only get involved in certain aspects of the programme that they develop such as layers and masks etc but don't know anything about other aspects of the programme.  This is similar to Microsoft where teams are dedicated to perhaps Office, Powerpoint and  Excell etc and again don't get involved with other parts of the software.  I personally have been using Photoshop since version 2.5 in 1994 and I certainly don't know all the programme.  Bear in mind that Photoshop started out by being a programme for graphic designers, and even today it contains lots of elements that I steer clear off because I never use them.
But compared to today where there are wonderful tutorials on the web and lots of digital magazines with tips and tricks, in 1994 I had to learn the programme from the manual.  Ever tried that?  One other suggestion which might be useful.  You might consider joining the National Association of Photoshop Professionals (NAPP's) that has a fantastic Help Desk.  Many times I have posted them a problem and they have come back with the answer in about 15 minutes.  But go for it.  It's a fantastic programme