yeah i mean being a fast learner helps you with like, what to play, but there's also a physical aspect -- how you play it. its something your fingers have to become comfortable with, almost second nature with. if there's one thing ive learned about bass, it's not like guitar or piano where if you hit all the right notes you pretty much got it down. being consistent with volume (on bass it's really easy to accidentally hit a random loud note that clips on the soundsystem/in a recording), playing firmly without the noise of the strings slapping against the pickups, even keeping a steady rhythm all requires very specific technique, like your fingers have to be firm but delicate at the same time. it's really hard.
im sure you know this but if you angle your hand downward to where your fingers are perpendicular to the guitar, it makes all this a lot easier.