For me a good explanation, that is strictly speaking true, is:
I had a trial period of not drinking and I've decided it's not for me anymore. I feel so much better without it—so much so that now I've lost the taste for it.
I know it sounds a little bit self-righteous but who honestly can argue with that? If anyone expected you to drink after that, they're basically saying they want you to feel worse—and do something you no longer enjoy doing.