We Were Happy (TV)

“We used to watch the sun go down On the boats in the water”

Water as the surface a happy past was lit from. The line sits inside the song's catalogue of small remembered scenes: the boats, the water, the sun going down, physical details the speaker uses to mark a relationship by where it was witnessed.

“walk along the streets”

Walking along the streets as the early-relationship register, two people moving together at the pace the foot allows. The line marks the relationship's first phase as the one in which the partners shared the streets rather than driving across them; the verb 'walk' carries the slowness the later song looks back on with the loss already in it.

“We used to watch the sun go down On the boats in the water”

The sunset is remembered rather than watched. Used to does the work before the image arrives, so the boats and the water are already lost by the time the light falls on them. The song confirms it two lines later, where the happiness is what makes the goodbye harder.