I'm sorry you drank Blondescorps, here are some helpful potential responses which I saved from another thread-
"No, thanks," is really all that is needed.
"It just wasn't helping me in any way in my life."
"I feel so much better without it."
"I've outgrown my partying days."
"I've decided to focus on my health and fitness," (of course, then there's health and fitness to focus on...)
"I'm taking a break from it to see how I like a completely alcohol-free life." You could use that for the next 40 years - "Oh, yeah, I'm still taking a break."
"I don't like how I feel when I drink," or, "I don't like the day-after feeling."