:-D @ jake-the-peg's analysis of when the rot set in :-D Look, it's not my country and language but we have the same kind of discussion over here (in Sweden), of course. Constantly.
Language is and has always been a living thing. It's an organism. Usages that don't fill a function fade away and die very quickly so sit back and relax:) What function, you may ask, could 'myself'' instead of 'me' or 'I' possibly fill? I don't know. Obviously *some* function! Sometimes it's just enjoyable to be able to choose between synonyms, sometimes you choose a certain synonym to display your identification with a certain group, sometimes a certain synonym sounds better - metrically, emphatically or otherwise - in a certain context than another option would have.* As QM says, your language is so wonderfully rich. We don't have a fraction of the words you do. Language doesn't become that rich by refusing to change. I was listening to Middle English the other day (so beautiful<3) and I couldn't make much sense of it. By the same token, our descendants wouldn't know if we were asking directions or trying to sell them a watch, if they met us on the street. ♫ ♪ It's a living thing... ♫ ♪ so get with the programme innit ;-)