The quick answer is that bread and wine during the Eucharist are not transformed into the flesh and blood of Jesus of Nazareth, but the glorified reality of the risen Christ. The sacramental signs of bread and wine are substantially (trans-substantiation), by the mysterious power of the Holy Spirit, become Christ present to us and in us. As Catholics, we receive the Eucharist (we don’t “take” the Eucharist). The sacrament achieves by signifying. A too literal reading of the words means one misses the deeper realities communicated by metaphor and meaning.
The deeper answer needs more awareness of what a sacrament is and how a sacrament achieves the mediation of God’s grace. The question presupposes a serious misconception about the nature of the realities of sacraments. Sacraments are relational realities.
I often ask college students, “If I put on all the vestments, and go down to the local bakery next to the liquor store, and prayer all the prayers in the Big Red Book, i.e. the Sacramentary, does all the wine in the liquor store and the bread in the bakery become the body and blood of Christ?” The best answer I ever got was the friend who told me, “No. But I don’t know why not.”
Eucharist is a communal reality. Eucharist grows out of, establishes and maintains relationships of love between us and God, and us and all in the church, through all of time.
“I” don’t receive communion alone. “We” receive communion. Eucharist makes us all one in Christ, an amazing reality. If we really understood and appreciated what the Mass is and does, we’d go every day. “One bread, One Body. One Lord of all. One cup of blessing which we bless. And we though many through all the earth, we are one body in this one Lord” (John Foley, S.J.). Read John Chapter 6. It’s all there.