I had been planning my 21st Vegas trip for months... and still managed to forget my fancy dress shirts after 4 hours of driving.
Luckily, Ross was only a few miles from our hotel and we spent some time walking around until we got there. Once there, i was able to pick up two dress shirts for $28 within 5 minutes! I was pretty pumped!
The only down side? if you're looking for an easy bathroom, "they don't have one"