Definitely a 'Your Mileage May Vary' moment here. On guitar, I used to 'slog' rather than 'power through' a song. It took weeks before it came close to sounding like music. Now I start with a couple (tough) bars (think Doc Watson, Deep River Blues) and that bit sounds like music in a day or two. Plus, I find muscle memory develops much more quickly when I play the same bit over in a short time span.