Why does something taste less sweet after eating something else that is sweet, especially if you don't drink water in-between.
It's a general flaw (IMO bad design) in organic/neural sensor frameworks where inputs tend to be measured relative to previous experience rather than absolute quantitative.
This happens with weights as well. There have been plenty of experiments where people are asked to pick up a heavy weight and then a light weight, then record/estimate the perceived light weight. The next day, they pick up a medium weight and then the same light weight and record the perceived light weight.
The 2nd recording turns out "heavier" because of relative perception.
Suggestion: Computer-mediated nerves designed to measure in absolutes.