Maybe it was the Buddha? He didn't shave, but just cut off his hair with a sword on the night of his renunciation. His hair didn't grow again.
The Vinaya rule allows monks to grow hair to a length of about 1"
The custom in Burma is to keep the head clean-shaven, so Burmese monks shave almost daily in some cases — I do it about once a month.
The Vinaya rule also prohibits the use of scissors to fashion the hair, so some say that an electric hair-clipper should not be used, but that misses the point. If the purpose is just to cut the hair as short as possible without shaping it, then that's fine.
I do both, first with a hair-clipper to remove most of the hair, then with a (safety) razor for a clean shave.