Most of us encounter the concept of nicknames when we're kids, as we come to know our friend James as Jimmy, Susan as Sue and so on, but these nicknames never really come with an explanation.
For instance- why is Richard shortened into "Dick"?
Turns out that nickname comes from the Middle Ages, when names were often shortened for the sake of brevity since they were written out by hand and rhyming nicknames were all the rage.
Richard became Rich and Rick, and for rhyming sake Rick became Hick and Dick, and for some reason Dick was the only one that stuck.
Now that one's not so strange, but how in the world did Margaret get the nickname Peggy?
Once again rhyming is to blame, as Margaret was shortened to Maggie, Meg and Mog, which then became Peg(gy) and Pog(gy). Still strange to call Margaret "Peggy" instead of Maggie or Marge, but Peggy is way better than Poggy!