Here's a good quote from Fr Brendan Freeman in his book Come and See:
The Eucharist is a mystery and as such cannot be fully understood by reason alone; faith must supplement our reason. But there has to be something we understand about it, something to hold onto and practice. I believe that by washing his disciple’s feet, Jesus is telling us something about the mystery of the Eucharist, something easily understood, something as easily understood as, who is more privileged? The one who serves the table? Or the one who sits at the table and is served? What does this tell us about the Eucharist? In the Eucharist, Jesus hands over his body and pours out his blood for us. Jesus’ words are repeated every day at the consecration: “This is the cup of my blood … it will be shed for you and for all. Do this in memory of me.” We know that our blood is our life force, our life. When someone says, “I offer you a cup of my blood,” they are saying very graphically that they are offering themselves, their very existence to us. Now, we cannot offer actual blood, but we can serve each other and in this way pour out our blood for the other. St. Benedict calls the monastery a school of the Lord’s service. As such, it is a eucharistic school, a place where we connect liturgy and life. However, you do not have to be in a monastery to be in this school. The message is so simple: serve each other and you will fulfill the law of Christ who came among us to serve and not to be served.