This was Lewis' first hit single and biggest hit. Along with this song, she wrote all the material for her debut album of the same name; during the early sixties, it was somewhat rare for a female singer to write her own material, especially for an entire album.
The backup vocals were provided by the Chicago-based R&B male group The Dells.
In 1977, a version by Yvonne Elliman reached US #15 and UK #26.
The song was covered by Julia Holter on her 2013 album Loud City Song, which borrows from the 1958 musical film Gigi. She explained to Fact Magazine: "There's a scene in Gigi where the creepy old guy played by Maurice Chevalier, who sings the famous paedophilic line 'thank heaven for little girls' is singing with Gigi's grandmother about a brief fling they had together decades before. In it, they can't agree on any of the actual details of their dates, highlighting the vagueness of memory. This kind of nostalgic haze of a past romance made me think that my cover of Barbara Lewis' 'Hello Stranger' would fit nicely onto this record."
"Lewis' song captures the vagueness of long-lost love so well," Holter added. There aren't really any details given about the relationship, just the conflicting feelings of loss and hope that come from a past lover's visit."