I have a long way to go. But I have learned, thanks to a bass teacher named Dale Titus, that it can be done with patience and repetition.
Oh, the learning regimen is fairly traditional: learn scales, learn modes, learn arpeggios. Absorb scale theory and how it relates to chords and keys. Learn every inch of the neck.
However, a lot of successful bass playing (or playing any instrument) is great execution. Getting your fingers on the right fret at the right time, without string rattle or buzz, plucking those strings accurately and quickly -- those skills are hard to attain. You attain them by playing exercises (Titus calls them "chop builders") slowly at first, concentrating on a good sound. You then slowly increase the speed of playing those chops until you can do it quickly as well as accurately.
So much of learning an instrument is developing the muscle memory to play it well and right. Break it into its various parts and learn each part well, taking as much time as you need to do it. Keep at it on a daily basis. If you learn one small thing each day, your knowledge and skill will accumulate faster than you think.
I think this principle works for mastering just about any skill or body of knowledge. It's like the old but useful analogy of the snowball rolling downhill.