Thanks for the comments folks.
I wish I could put my finger on what it was that's made me feel so different this time around.
Something clicked in my mind that made me want sobriety rather than need to stop drinking. This thing, whatever it was, has been vital in my seeing being sober as a positive choice rather than a necessary evil.
I know I've got a long way to go and I'm still far from sorted - I have recently noticed a degree of short term loss memory and have trouble finding the right words on occasion - but these will hopefully improve with time and are far less debilitating than the effects I experienced while drinking.