I did spend a fair bit of time trying to learn to crochet in the 'approved' manner - i.e., yarn in left hand, etc. - simply because I thought it would be nice to be able to use yarn with a metallic thread in it. I was crocheting a throw for friends based on a stained glass motif (duly acknowledged when I was in Ravelry), and a black with metallic thread would've been perfect for the 'leading' parts ...
But I simply couldn't maintain it. I mean, I did understand what I was being told, and did manage to actually do it; but I couldn't keep it up! - my fingers were far too used to my 'single needle knitting' style. So the throw was made with plain black for the leading.
And here it is ... you can imagine what the flecked black would've looked like; and so I do regret my inability to DO IT RIGHT! - but only for that reason! :-)