If you look like a monk...

Last week I was hanging out with my friend, Br. K. I told him that I'd like to read the books on the postulancy reading list for his monastic order over the summer, and he asked me again if I was interested in joining the order. I told him I didn't think I was called to monk-hood, and he said something that stuck with me, "You know, if you look like a monk, and act like a monk, you might just be a monk."
Now I'm not making any plans to become a monk, but it's made me wonder what is it that makes someone a monk?  What is it that defines the monastic life? The priesthood and other religious leadership roles seem so clearly defined, but monastics aren't.  They aren't marked by vows of celibacy, because some monks aren't celibate.  They aren't marked by communal living, because some don't live in community.  What is it that marks these lives?
It seems to me that what ultimately marks a monastic life is a commitment to living in right relationship with God, a devotion to a simple lifestyle without a materialistic focus, a lot of prayer, a lot of sharing life together in an honest way, and a shared calling to a collective mission.  Maybe that is too simple of a definition of a monastic life. I don't know. But if that is the definition of a monastic life then Br. K was right.  I might just be a monk.
 Am I going to join an order? I would never say never, but not in the foreseeable future.  I currently do not feel called to take on the robes and the label, but I do enjoy sharing life with others and strive to commit more of my life to prayer.  I think I'll just live as someone who is monastically inclined.