I've been doing this for years. 22 - 23 years, to be exact. Most recently, it's been with The Amity Affliction's 'Misery' and Ozzy Osbourne's 'Patient Number 9'. Before that, it was Nightwish's 'Human|Nature'.
It's just how I've always listened to music. I'll listen to a apecific album until I know it like the back of my hand. Then move to the next one. I eventually go back and realise what a good album most of them are, and wonder why the hell it's been so long lol