Iron Maiden, I somehow thought it was just the soundtrack for the movie Iron Man.

Turns out it's one of my favourite bands.

Daft Punk, I thought I hated it because "One more time" played so many times on the radio and literally everywhere back in the days, that I developed hate for it, but turns out their songs are actually good, specially Random Access Memories.

There's also the opposite, songs I used to like but because playlists repetition I started to hate, like Cranberries' Zombie, What's Up, Lennon's Imagine, AC/DC's Thunderstorm, Radiohead's Creep and some of Rammstein's music.