Songfacts®:

• "Younger Girl" is about a guy's a crush on a girl who is too young for him. In the song, he wonders if he should just be "acting like a brother" for a while, biding his time until she's old enough to date.
  
  The problem is that the waiting would be even worse than not waiting. "If I wait I'll just die, yeah." So instead he's left her behind, but can't get her out of his mind.
  
  The song's most poetic line is, "She's one of those girls who seems to come in the spring," with spring being a symbol of renewal and youth.
• The song was written by lead singer John Sebastian and included on The Lovin' Spoonful's debut album Do You Believe in Magic. The song is clearly inspired, consciously or otherwise, by the 1930 Gus Cannon's Jug Stopper's song "Prison Wall Blues." The songs sound almost identical, but with different words.
  
  It's not the first time the Jug Stompers' music pops up in the '60s. Their song "Big Railroad Blues" was covered by the Grateful Dead and appears on The Music Never Stopped: Roots of the Grateful Dead, which collects songs from acts that were particularly influential on the Dead.
• The Lovin' Spoonful version wasn't released as a single, making it ripe pickings for covers. The Critters, who had a hit with "Mr. Dieingly Sad," had the biggest hit with the song, taking it to #42. The Hondells of "Little Honda" fame reached #52 with their rendition. Both covers peaked in July 1966; The Critters version also made #38 in UK, #18 in Australia and #9 Canada.