Playing octaves was just a coincidence. And it's still such...

Playing octaves was just a coincidence. And it's still such a challenge, like chord versions, block chords like cats play on piano. There are a lot of things that can be done with it, but each is a field of its own. I used to have headaches every time I played octaves, because it was extra strain, but the minute I'd quit I'd be all right. But now I don't have headaches when I play octaves.