In reality, no kids is trained in just a three days. Sure they get the concept in three days, but the grasping of the concept is only the beginning. Those parents fail to mention that their kid will forget to pee while playing with a toy. Or that their kid later regressed for one reason or another. Or that sometimes their kid is trained to do #1 in the potty, but refuses to do #2.
The real truth is that having potty trained kids isn't all it's cracked up to be. Initially, it means stopping what you're doing every two hours to take your kid to the potty. It also means chasing them around the house convincing them to put their underwear back on. It means getting very adept at finding suitable trees that need watering. It may mean less stinky trash, but it also means more stinky laundry.
Since I insisted on having my son trained before his little sister arrived (no way was I changing diapers on two kids daily), I also have many memories of lifting him onto or--in some cases--floating above a public toilet while very pregnant. Maneuvering a squirmy kid in a germy stall was not the easiest thing to do while the size of a houseboat. Amber Dusick describes it best in Public Toilets vs Newly Potty Trained Kids. The toilet is the enemy in those early months.
If your child isn't potty trained--don't worry. It's not a reflection of your IQ nor his. Enjoy the cleanliness of the changing table while you can because you will soon meet the enemy in his truest porcelain form.