LAS VEGAS — IT’S the time of year for resolutions. Lose 20 pounds, get to the gym, eat healthier, be more productive, whatever. But in a few months, many people will let these goals fall by the wayside, to be revived next year. I belong to a group who can’t afford to make pledges we don’t keep. I’m an addict.

For addicts, discipline isn’t something to strive for each new year; it’s necessary for every moment. Though it might be surprising — considering all the craziness associated with the Mike Tyson persona — one of my best qualities is my unerring discipline, which my mentor and first trainer, Cus D’Amato, instilled in me. Cus and I worked hard so I could become the youngest heavyweight champ in history; I sacrificed most of my social life as a teenager and for years pushed my body to extremes every day, just to repeat the brutal regimen the next day.

Cus died a year before I won my first belt, in 1986. With him gone, I had less of an incentive to stay disciplined, and I started drinking heavily and taking drugs. I finally retired from boxing in 2005. I didn’t want to insult the sport by coming in out of shape, just fighting for a payday. That’s when I became a full-on raging addict. Since then, I have struggled for sobriety, sometimes successfully, at other times not.

Even though I possessed incredible discipline when it came to boxing, I didn’t have the tools to stop my slide into addiction. When I got a chance to get high — boom, I’d get high. I wouldn’t call my sponsor, wouldn’t call my therapist, wouldn’t call my sober companions.