text: You're right.  In the early days there were only bishops.  Only they had sacramental powers.  They celebrated a meal together, but because there were no priests, there was no Eucharist unless a bishop was present to change bread into the body of Christ.  Sharing a meal in Christ's memory does not make a Eucharist.  Can. 900 §1 says "The minister who is able to confect the sacrament of the Eucharist in the person of Christ is a validly ordained priest alone."