Your brain definitely works differently when you play an instrument of the opposite "polarity" to your handed-ness.
If that wasn't the case, and it was just as easy to learn either way round, there wouldn't be any market for left-handed instruments.
You can understand a left-handed person deciding to persevere with a right-handed instrument, because basically, just like everything else, the world is set up for right-handed people, and it gives you more options.
A right-handed person playing a left-handed instrument is far more unusual.

"it will damage the speakers (eventually), but not the amp."
Not with this amp :-) The 6CA7s are almost completely knackered, but it still sounds OK.
I've actually got a 100 Watt subwoofer that I'm going to try plugging into one of the spare sockets on the speaker box.
It's truly astonishing what that can do.