Dating myself, but I remember the first time I heard about mp3s. In a school trip, another kid told me that you could download songs in files that were only a megabyte a minute. I was incredulous. Up until then songs were wav files and video was in massive QuickTime files that took decaminutes to download for tiny snippets. Turns out he was right though :)
Interestingly, it looks like Fraunhofer (much to its later regret) released the first real-time MP3 player (didn't have to be decompressed first) in 1995: <a href="https://en.wikipedia.org/wiki/WinPlay3" rel="nofollow">https://en.wikipedia.org/wiki/WinPlay3</a> ... the only option until Nullsoft's 'WinAmp' came out in 1997.