I have had a string go a few times - and as most of my guitars use Floyd Rose or Kahler floating trems it forces you to learn how to bend accurately - for melody lines it isn't too much of an issue, but as each string needs to be bent a different amount, chords become really good fun.

I remember once having burst a string on my main guitar so I was playing the spare while my tech was changing strings - middle of a cover of a Van Halen piece and at the end of the solo I killed the D so for about 2 bars I was figuring out how far out the other strings were, then had to play a whole verse with odd bends on before I could get time to tweak the bridge tuners.

Still, it worked right so hopefully I didn't look too much of a git for not having another spare.