Shave and a Haircut, Two Bits

Shaving does not cause hair to grow back thicker, or coarser, or darker. This belief is due to the fact that hair that has never been cut has a tapered end, whereas, after cutting, there is no taper. Thus, it appears thicker, and feels coarser due to the sharper, unworn edges.

Hair can also appear darker after it grows back because hair that has never been cut is often lighter due to sun exposure. I have noticed the hair on my head has begun to grow in, because it sure isn't growing out like it used to.

PS - Two bits is an old expression in the US for 25 cents. It dates from colonial days, when a common unit of currency was the Spanish dollar. As a way of making change, these dollars were often cut into eight pie-slice shaped pieces, called bits. Hence, two bits being a quarter dollar.