I like sweet things. I totally confess that I eat way too many sweet things. 3 or 4 times in my life I've "challenged" myself to go 30 days without eating any sugar except what's in fruits and vegetables and food like that naturally, making sure to eat a very careful diet and no treats or processed food. Every time within a few days I was having awful cravings and mood swings, and by a week I felt like an emotional wreck who just wanted sugar. I completed my "challenges" but it was disturbing.
It also gave me a ton of empathy for addicts. If I can't not eat sugar without a massive struggle, I can only imagine trying to get clean from heroin or another drug.