Those suckers are bizarrely addictive. It's one thing to have one shortly after you wake up, but I found myself craving them later and later in the day, and of course that makes it harder to sleep...which makes me more likely to have energy drinks the next day.
I stopped the daily consumption when I realized I was having around 800mg of caffeine a day, which couldn't possibly be good for me. I quit energy drinks cold turkey and just did Diet Coke, which I cut off at 2pm; even with that weening off I still got headaches and felt miserable for three days.
I will still occasionally consume an energy drink if I'm traveling and I need to wake up super early, but thankfully these are very outlier events.