From my experience, your "intake treatment person" is indeed telling you some truth, but it doesn't necessarily mean that he should be your approach to quitting drinking. I would definitely proceed with caution under any circumstances, though. I also wholeheartedly agree with all of the follow-up posts above as well.
Your story is very similar to mine in many repsects, for I was strictly an evening drinker, and for some reason I was able to carry on in life without many people knowing I was an alcoholic. In addition, on occasion I was able to abstain from drinking for three or four days without the skakes or any kind of withdrawal symptons. All it took for me was one night of binge drinking to send me spiraling into a whirlwind of anxiety and panic attacks where it felt as though I might have been having a stroke or a heart attack. It was at that point I decided to quit, and I really regret not seeking treatment of some kind, because my detox period was absolutely horrible. Even after I had quit drinking for about three weeks while feeling better, I over-exerted myself while shoveling snow and ended up with a mild heart attack followed by a two-day hospital visit. In the end, not only did I have anxiety/panic attacks as well as a heart attack during withdrawal, but my blood pressure was through the roof, too. I honestly wouldn't wish this experience upon anyone.
So, when people tell you that withdrawal can be dangerous and deadly, believe it! I would suppose that the severity of withdrawal symptoms can vary depending on how much one drinks, but if someone has been drinking regularly and heavily for a relatively long period of time, my guess is that the withdrawal process will be all that much more severe. At the very least, I'd seriously consider consulting with a doctor so that you can have a sobriety plan of some kind to ensure that your detox period becomes as tolerable and painless as possible.