Everybody was referring to this product: that it should stung, but I do not experience any discomfort... I applied today for the first time after 1 month to be on The Regime as advised. Cleanser, Treatment and Glycolic Acid (AHA) and nothing tremendous as everybody else were writing.... No itching, no burning, no stinging... Do I do something wrong?

It is not the same for everybody. Like you I never experienced any itching or burning or stinging. Consider us lucky!

Some people just have tougher skin than others.

I also didn't experience any redness or burning or stinging but then, as bkubs says, some of us may have tougher skin than others.

As an "older person" that's probably my reason.