Maybe you think there is only one kind of Rubik’s cube in the world which is 3 by 3, do you really think only the easiest 3 by 3 can make itself famous around the world, if you say “Yes”, you are naive. The picture you can see shows the collection of my and friend's Rubik’s cubes.

 The 3 by 3 is the entrance ticket of the world of Rubik’s cube, but even this simplest Rubik’s cube has 43,252,003,274,489,856,000 different situations you can come up with. Let’s say you can rotate thee Rubik’s cube 3 times a second, you need 454.2 billions years to make all the situations, this number is about 3 times the age of the universe. If you want to solve a 3 by 3 Rubik’s cube logically even by a easiest way, you need to remember about 60 formulas, furthermore if you want to solve it faster you need to remember thousand of formulas. That’s the only the basic one there are hundreds and thousands kinds of Rubik’s cubes exist in the world, if you want to solve them all, you really need to spend a bunch of time.

Here is the video shows the fastest Rubik's Cube solver.