Riptide

: Some describe grief not as a wave that passes, but as a riptide—unseen and cruel, pulling you under when you least expect it.

Beyond the music, "riptide" is often used as a metaphor for dealing with intense external forces or emotional distress. Riptide

The Riptide Mentality, Lesser Goals, & More | The Curiosity Chronicle : Some describe grief not as a wave

“The chorus ties into this. A riptide suddenly swallows you beneath the water before you can react. He's fallen into this relationship without thinking.” Reddit · r/LyricInterpretations · 8 years ago but as a riptide—unseen and cruel

: This idiom suggests someone who is delicate, refined, or being kept "safe" and secluded from the world.