Off-topic digression here ...
Group 1 people need only see a knot tied once or twice and it's their for life whereas it is near impossible to teach group two how to tie even a simple clove hitch
You are right. In some cases I think it is just a matter of how good a person is at visualizing things. In other cases, I think that the person could do better by being taught better -- more logically.
Even people for whom knots are hard, though, can learn them. For example, I cannot believe all rock climbers are gifted with knots, but they darned sure learn certain knots if they want to be safe.
You can go surprisingly far by thinking of bights and loops.
* A square not is just two intersecting bights, as are a bread knot and a granny knot. The difference between the square knot and bread knot is just which side the ends are on -- that matters in many knots -- square knot, sheet bend, and bowline are common examples of that.
* Both a sheet bend and a bowline are a loop and bight intersecting. Cut the big loop in a bowline and you cannot tell which knot you started with.
* A double carrick bend is two intersecting loops.
* A half hitch is just a loop around something. Two of them, around the standing part, is two half hitches. Two of them around a stick is a clove hitch.
* A "slipped" or "slippery" knot is just making the last step be pushing a bight through instead of the end. Such knots generally hold as well, and are far easier to untie.
* You tie shoelaces with a double-slipped square knot (or a granny knot, but the square will stay tied better).
As an example of thinking this way, consider a trucker's hitch. The easiest way to think about how to finish it is that you tie the end through the bight, formed by the initial slip knot, as a sheet bend -- or, my preference, a slippery sheet bend (so it will be easy to untie). It is far easier to remember a tucker's hitch as a slip knot, finished with a sheet bend than to try to remember it a one big knot.
Making it easy to remember is not just a gimmick -- I find a trucker's hitch much better for tying things down (including guylines) than any of the slipping knots (such as a tautline hitch). Done in the slippery way, it is easier to get really tight, just about as easy to adjust when needed, and far more secure.