Why should I buy a 50mm prime lens?

Challenge #5 in the Opportunities series. Hosted by juanlucas.
Challenge has finished
I made a mistake... haven't bought a 50mm prime lens yet. Show me why I should buy it!! MANDATORY to indicate brand/model of lens used for taking the picture (of course, only 50mm prime lens for this challenge).
Show full rules
submission
phase has
ended
94 entries
voting
phase has
ended
1944 votes
Indoor Smoking Ban
Click here for full size original image
44th place (joint)
2.405
 
low
high
Guy smoking outside bar (you can see that) because of indoor smoking bar (I'm telling you). The Nikon 50 mm f1.8 is unobtrusive, light, fast and cheap. Photo taken at 800 ISO because I was indoor seconds before... I didn't have the time to change settings.
Camera:
Lens:
Submitted: Monday, 27th June, 2011 16:50 (GMT)
Taken: Monday, 18th April, 2011
Focal length: 50 mm
Shutter speed: 1/2500 sec
Aperture: F5.6
ISO: 800
Notes: Nikkor 50 mm f/1.8D
Views: 145
Galleries:
Provide complaint details
Your complaint (along with the complaints of others regarding this entry) will be reviewed by the challenge owner. Depending upon the nature and applicability of the complaint, the entry may be disqualified. In extreme circumstances the user who submitted the entry may receive a ban from the challenge or series in question.
Reason:
Comments:
Saving ...
Complain
Keyboard shortcuts:
p previous n next c challenge f full size r retract vote # vote