Example:
Doughnuts. My child asks for them as a special treat. We make the date. We visit the hole-in-the-wall doughnut shop. We browse for our favorites: maple bar for her, perhaps an old-fashioned for me (or a bismark, apple fritter, cherry turnover, etc.). They smell yeasty and sweet. The sugar is pleasant, but then the fat begins to coat my teeth and mouth. Pretty soon it seems to hit my gut. Gas follows sometime after, and perhaps a Tums-worthy moment. Hopefully it won't seek a rampage on my bowels.
That's a lot of displeasure for a nice smell and an initial sweet sensation. What I find most interesting is that I still believe I crave them.
Stupid doughnut lust.