[derriz]

I know what you mean - took me a while too. I understood what it does, how the parameters affect what it does and the mechanics of it, but struggled to "hear" it.

I even bought a cheap $25 Behringer guitar compressor pedal to see what I was missing but it didn't help - later I realized that my guitar playing isn't repeatable enough. So this isn't the way to go.

What made it click was due to an accidental mistake in my normal workflow - I recorded some DAW-less techno jam stuff using GarageBand (normally I just copy the wavs from my little Tascam). While playing back, I noticed that there's a master compressor and I started fiddling with it. With repetitive music like Techno and House, the difference between no compression and full compression suddenly becomes very apparent (although still somewhat subtle compared to other FX commonly used in music production). Also it helped that my recording had no compression on it - comprising just a raw drum machine and mono-synth.