...my brother was right to wonder recently how he managed to learn the violin and I managed to learn to play the bass, considering that neither instrument had frets. I know that with practice, we got the feel of where the notes were, just as typists learn where the correct keys are.
Looking back, however, learning Classical pieces in middle school through college that professional symphony musicians play strikes me as almost miraculous now. How does any musician become that intuitive on a fretless instrument?