I am so smart! I am so smart!

[Sabre]

Completely possible, but if it's taken accurately and honestly then the differences in the outcomes will be negligible giving roughly the same results.

Not nearly to the same extent as it is when learning something like a video game or riding a bicycle.  A person's mental capabilities/capacities don't really change that much over one's lifetime, unless one gets really old and gets a mental related disease or while they are still growing up.

Not what I heard. It's basicly a series of puzzles. You can become good at those. eg. a maths puzzle in it would be easier if you studied maths the day before.