If you find melodeon a bit mind-bending, you may find the English concertina even moreso

There's a whole area there - how different people's brains are wired differently, and how that affects which instrument(s) they play.

I have spent hours and hours and hours with various borrowed melodeons down the years, and at the end of all that effort I have still only got a less than 50% chance of producing two consecutive correct notes, and that with the greatest of concentrated mental efforts.

EC, by contrast, I picked up the absolute basics of reasonably quickly. Yes, I'm still rubbish compared to Robert Harbron or Simon Thoumire, but I'm also infinitely closer to them than I would ever get to Andy Cutting, Ricardo Tesi, or even Mike from Powderkegs who started playing melodeon last year.

Yet other people's brains implode whenever they try to play EC but after half an hour on a melodeon can stumble through half a dozen tunes.

I don't know why that is, but I know it happens, and I guess that why we all end up playing different instruments.