It is, in fact, possible to have good handwriting without someone smacking your hand over every mistake.
I was lying in bed this morning and thought up the perfect metaphor to describe my childhood and 20's: Imagine a child confined from birth and forced to live in a small box. The box is big enough for a child, but inadequate as he grows. He's not allowed out of the box however, and so as he grows his limbs and spine grow gnarled and crooked. When he reaches adulthood, he is allowed out of the box, but his body is deformed and useless, and he can't do anything but envy the healthy people around him. To have any chance whatsoever of living a normal life, he has to un-deform himself, snapping his own bones and resetting them in an arduous and painful process. Nobody can help him with this process, because nobody else knows about the box and cannot relate. Over the course of more than a decade, the bone breaking and resetting process feels almost complete, but the child can never be sure if his achievements are ever anything more than superficial imitation, as he doesn't naturally know what his skeleton SHOULD look like, and instead was forced to imitate the size and shape of the people around him. Because the child cannot see inside himself, or see inside of others, the comparison is always guesswork, so it is impossible to know for sure if he has succeeded in rehabilitating himself, or if he's just created a twisted imitation of a natural human shape using his own body. It may be impossible to know for sure.