This hasn't changed in at least 2 decades: I was getting zapped by Apple metal laptops circa 2004. But I have never encountered this problem when using a grounded plug.

It was also a lot worse for me when plugged into outlets in an old house in Mexico, especially when my bare feet were touching the terracotta floor tiles; it's not really an issue in a recently re-wired house in California with a wood floor, using the same laptops, power strips, etc.

If you are having this issue and you currently plug a 2-pronged plug into a grounded outlet, try using Apple's 3-pronged plug instead, and I expect it would go away. If you don't have grounded outlets, then that's a bit more complicated to solve.

That's what confuses me, I am using the cable with three prongs, it is grounded. I am beginning to suspect some other appliance I am plugging into it that is responsible of the build-up of charge, but then why is it not finding its way to the ground... something doesn't add up but has been my experience consistently.

Perhaps the outlet isn't properly grounded?