this guy sounds like a professional "recoverer" - multiple detoxes, multiple rehabs, multiple turning over the new leaf. i say "professional" because some people become quite practiced in SOUNDING like they are IN sobriety, they know the lingo, they know what the concerned loved ones WANT to hear. they can Talk the Talk.
but then soon enough, they return to their "other" normal. living the life of a drinker, with a good dose of lies, deceit, and game playing
what they are NOT doing is Walking the Talk. truly living a brand new way, with a brand new attitude and outlook.
in time you can look at what the HOOK was for you. what was it about this person who displayed such issues and problems that made you decide to hop on the rollercoaster and strap in.