Some very good posts above that go to prove, as if it needed proving, that there are a number of very wise heads here at MT when it comes to martial arts ... who'd have thought it? An MA site where people know what they're talking about :lol:.
It's an embarassing story to recount in some ways but one of the reasons why I had such a bad opinion of the Ninjitsu (yes, I know but that's how I learned to spell it first

) chaps when I first joined here was my real world experiences with wannabe black pajama 'fighters'. Those people who bought into the Ninja Myth when it crept out of the shadows over here in the '80's.
I met a couple of these in my empty-hand days who were really keen to show me just how superior what they had learned from the books they had ... right up to the moment when they ended up on the deck

. I even, to my undying shame, remember telling one chap as I helped him up "Books don't hit back!".
Other than that somewhat 'guilty pleasure', I have nothing terribly substantive to add to the points already made except to elaborate a little into the area of
armed arts. Here the 'self-taught' route is even more problematic and doomed to failure of the bloody kind.
It is also one where the 'back garden baton twirlers' {they get ever so aggressive when you call them that :angel:} seem to run off at the mouth even more than the Pretend Ninjerz brigade.
I have had one of these actually 'call me out', so to speak, when I dared to criticise his
swordwork on YouTube. I was tactful enough not to do so via public comment but made a private mail explaining that whilst what he was doing looked fine on video, it was not a sword art and he should not fool himself into thinking it was.
Cue bluster and offers to "see who was 'the man'". I said that ordinarily I would not think of doing such a thing and pointed out that I was not particularly well trained myself yet, only having studied for a couple of years but that if he was willing to accept the risk we could accidently hurt each other, then I was game.
Cue silence.
My point is that such people do fall into two camps. The 'Blagger' and the 'Self Deluder'. The former knows that they're talking nonsense but likes to see if 'talking the talk' is sufficient to be the Big Man. The latter is in some ways worse but at least more honest because they truly believe that their self-taught skillz are the bees-knees.