Physical and psychological traits matter when you undertake certain tasks - how many fast twitch muscle fibers you have, how big and string your lu game and heart is, the angle of your jaw in relation to your brainstem, the distribution of your weight on your body, your personal nerve conduction velocity, your natural aggressiveness and your pain tolerance levels for boxing.
Your natural intelligence, hand-eye coordination, tolerance for failure, and curiosity level for learning programming.
Your hand-eye coordination, imagination, and depth of color vision for painting.
The thing is, while everyone starts with more or less of some physical or mental fitness for a particular task, with enough proper training the difference between two trained professionals is very, very small. Yet o e is Mohammed Ali, and one is Leon Spinks. That difference is not in proportion to the difference in their physical or mental capabilities at the start, and is largely explained in studies by coaching and practice technique.
The ability to follow a trainings regime until you reach success is largely a mental tolerance for failure and determination. If you have lots of success, you tend to continue. But if you were to continue despite failure, you would eventually reach the success you were after if the training regime was correct.