This might not be terribly helpful but this is what I do.
To learn a song, as others have said, work on it measure by measure but try to associate what you're doing, not with some abstract numbers on a stave but with musical sounds.
So when you do a 1-4-5 forward roll, you're not thinking of it in those terms but you're hearing the sound it should make and then you make it. You CAN be thinking "forward roll here, 1-4-5" but at the same time you should also be hearing the sounds that come with that movement. Eventually it all starts to get mixed up so the you can think the abstract but hear in your head the sounds. Sing the tune in your head and play it as you go along.
So for instance, with beginning of John Henry I go:
Intro: I hear the four note intro and I play it. There are quite a few tunes that start like this so I hear the four notes and I play them.
Then there are the first notes of the melody. I know this is based on a C chord so I use that position. I know there is an E in there so I play that. But at the same time I hear the melody and my fingers just play it.
Then there's a C(?) lick where you play on the 2nd string. I've played this a thousand times now so while I do think 'lick with the 2nd fret 2nd string', it's become almost automatic. So I hear the lick and I play it.
But I don't think in terms of those numbers on lines. I usually spend one or two days learning the tab (mostly just a day now, after 10 months of playing) and then throw it away. I use .tef a lot, as much as the tab sometimes, so that I can associate the movement of my fingers with sounds, so that the movement of my fingers makes 'sense'. Sometimes I'll refer back to the tab after a few days if I get stuck on some phrasing, where I hear the tune but can't find it with my fingers.
So as I read this, I don't know how much sense it makes. It makes sense when I play though.