Objection: nobody had a collection of MP3s in 1995. The computers of 1995 didn't have the power to decompress an audio encoding like MP3 in real-time without an accelerator card. People swapped MIDI arrangements of popular songs, and some folks ripped PCM audio directly to WAV files (where it then took up half their 1GB hard disk, so this was mostly a novelty—unless you were the proud owner of a $2000 1x CD burner to burn the PCM audio back onto.)
MP3s became a big thing around 1999, with better computers and the release of Napster.
WinAmp itself was released in 1997, but wasn't immediately popular because people didn't have music on their computers to play using it. It took off around 1999 as well (which is why everyone remembers Winamp 2, rather than Winamp 1.)