Sleepwalking

This song was originally written by a guy called Peter Gutteridge. He was one of the founders of the "Dunedin Sound" a musical scene in the south of New Zealand in the early 80s. From there it was covered by "The Clean" one of the early bands of that scene (he had originally been a member of in it's early days, writing a couple of their best early songs). The Dunedin sound, and the Clean became popular on american college radio in the mid to late 80s. I guess Yo La Tengo heard that version. Great version of a great song,

Ed Sheeran sings about missing his former partner and learning important life lessons in the process on “Punchline.” This track tells a story of battling to get rid of emotions for a former lover, whom he now realized might not have loved him the same way. He’s now caught between accepting that fact and learning life lessons from it and going back to beg her for another chance.

“Head > Heels” is a track that aims to capture what it feels like to experience romance that exceeds expectations. Ed Sheeran dedicates his album outro to a lover who has blessed him with a unique experience that he seeks to describe through the song’s nuanced lyrics.

“Plastic Bag” is a song about searching for an escape from personal problems and hoping to find it in the lively atmosphere of a Saturday night party. Ed Sheeran tells the story of his friend and the myriad of troubles he is going through. Unable to find any solutions, this friend seeks a last resort in a party and the vanity that comes with it. “I overthink and have trouble sleepin’ / All purpose gone and don’t have a reason / And there’s no doctor to stop this bleedin’ / So I left home and jumped in the deep end,” Ed Sheeran sings in verse one. He continues by adding that this person is feeling the weight of having disappointed his father and doesn’t have any friends to rely on in this difficult moment. In the second verse, Ed sings about the role of grief in his friend’s plight and his dwindling faith in prayer. “Saturday night is givin’ me a reason to rely on the strobe lights / The lifeline of a promise in a shot glass, and I’ll take that / If you’re givin’ out love from a plastic bag,” Ed sings on the chorus, as his friend turns to new vices in hopes of feeling better.

In the 1980s, sunglasses were a common fashion for people who wanted to adopt a "tough guy" persona (note all the cop shows from that era -- Simon & Simon, Miami Vice, etc. -- where the lead characters wore shades). So I think this song is about a guy who wears shades as a way of hiding his insecurity after learning that his girlfriend is cheating on him. He's trying to pretend that he's a "tough guy" to hide the fact that his girlfriend's affair is disturbing him.