before it was cool

Prepositional phrase

idiomatic

(idiomatic) Before (an idea or activity) was popular, trendy, famous, or duly appreciated.

Japanese Meaning

流行が始まる前に / 人気や注目が集まる前に / 一般に認知される前に

I was into vinyl records before it was cool, so my collection is huge.

私はビニールレコードが人気になる前から好きだったので、コレクションがたくさんあります。

Sense（1）

(idiomatic) Before (an idea or activity) was popular, trendy, famous, or duly appreciated.