I think normal drinkers get hangovers, in fact i know they do.
The reality is when I was 19, I was the least hungover of all of my friends the next day and I'd be back partying that evening when many of them were not.
In fact, this is one of the early indicators of being susceptible to alcoholism - great tolerance and mild hangovers. (see the book Under The Influence)
It is only after I hit my 40s that I started having the 4-alarm hangovers that come with 2 decades of hard drinking, and those, I am sure, none of my non-alcoholic friends have ever had.