The unknown
Pethro is the 14th rune in the runic alphabet. Shaped like a vessel when flipped sideways, that is its literate meaning; a cup. That can be interprented in two ways: either a cup to be filled or a gambling dice cup. It also represents female fertility.
While there is evidence that supports all of those meanings, I prefer the first one. A cup to be filled.
An empty cup, to be filled with whatever you want. It can be half empty, or half full, but it is yours to fill and to drink from. The possibilities are endless, limited only by your imagination. Because only you can control it.
I like to think of perthro as the way someone views life: it depends on your prespective, on the way you see things. It can symbolize the uncertainities, difficulties, trials and events that happen in your life, but also the free will with which to navigate them. How you handle things that are unknown, and how you plan for the future, can tell a lot about what type of person you are.
Thus, perthro is associated with mystery - there is more to life than we know, and more to be revealed. It is a mystery in the same sense an unborn child is a mystery. The possibilities are endless. Anything you ever wanted to be, and what you will be, in the end, all in a cup.
Everything you pour in there, is essentialy who you are. Which is exactly why you should be careful while filling your cup. Monitor what goes in there, all the possitive and negative emotions, all the experiences, the encounters, the people you meet, the memories you create. They should be filtered before entering. Everyone wants to be happy, but not everyone pays attention to what goes in the cup, to the way they face the unknown. If your cup is filled with nothing but misery, how can you drink happines?
But we are only human. We cannot always control it. No one can control fate. And so, the good and the bad, all together. Because perthro, does not discriminate between good and bad, black and white. In the hands of fate, that is an oversimplification of life, and it is not divided in two simple categories. Life is bigger than that.
Afterall, "The beginning and end are set. What’s in between is yours. Nothing is in vain, all is remembered.”
Sources:
http://runesecrets.com/rune-meanings/perthro
http://www.runemeanings.com/perthro