You know, I had EXACT the same experience! A collegue of mine was playing a tape of I&W at work, and although I liked what I heard, it didn't hit me.
Then I got a short relationship with a gf who introduced met to bands like DT, Savatage and Psychotic Waltz. She played WDADU and I&W like mad, and still, it didn't completely did it for me.
Years later, after hearing Pull me under and Another Day, I went out and bought I&W, SFAM and Awake. BAM!! SFAM hit me first, though. Never looked back since.