[angry_moose]

I still remember writing something in high school along the lines of:

  i=0  
  while(i<1):  
      <something with i>  
      i=i+.1

And spending hours trying to figure out why it ran an extra iteration, and this was early enough it wasn't easily googleable. Whatever I was doing with i needed it to be .1, .2, .3... and thought I was being clever not doing 1...10 and dividing by 10 every iteration within the loop. I think there was also a weird language quirk with whatever I was using that a print(i) rounded to a handful of decimal places so it looked fine while debugging it.

Very frustrating, but in retrospect very eye opening.