Yes! You! Stand still laddy!!

> Calling them "random" was a guarantee of the imminent meeting of a chalk board eraser and my head.

But then again, if your string generated by a good PRNG is "short enough", it will be "random enough for your purpose".

Note that good definitions of randomness are quite recent too, so your prof may have been exceedingly brutal to you:

http://en.wikipedia.org/wiki/Algorithmically_random_sequence