He worries that if his partner realizes how much he loves her, she will "run, run away," leading him to "water his feelings down" to stay safe.
Puth described the "too-loud" guitars as representing an overactive brain that can't sleep due to racing thoughts. Musical Composition Charlie Puth - Charlie Be Quiet! (Lyrics)
Charlie Be Quiet! - song and lyrics by Charlie Puth - Spotify He worries that if his partner realizes how