It took me to about level 12, 13 or 14 to become .95 confident that I had learned to solve any solvable puzzle consisting of a 3-dot region and a 4-dot region using only 2 slices. (My probability that I had learned started rising fast 2 or 3 levels earlier, but it took a few levels to reach .95 confidence.)
I.e., my curiosity over whether I had learned a general solution to that class of puzzle kept my interest.
But more importantly, I enjoy purely perceptual tasks. There is almost no cognitive skill involved for example in piecing together a jigsaw puzzle or playing a game of billards. (At very high levels of skill, maybe billards demands significant cognitive work, e.g., leaving the table in a state designed to exploit weakness in one's opponent's skills, but that does not apply to the game under discussion.) Maybe the difference between you and I is that I enjoy purely perceptual tasks whereas you do not.
I.e., my curiosity over whether I had learned a general solution to that class of puzzle kept my interest.
But more importantly, I enjoy purely perceptual tasks. There is almost no cognitive skill involved for example in piecing together a jigsaw puzzle or playing a game of billards. (At very high levels of skill, maybe billards demands significant cognitive work, e.g., leaving the table in a state designed to exploit weakness in one's opponent's skills, but that does not apply to the game under discussion.) Maybe the difference between you and I is that I enjoy purely perceptual tasks whereas you do not.