Certainly not to live a self-centered life. We have to make choices about how we will use the freedom we have. Because they want to serve God within the Church, diocesan priests make a formal promise of obedience to their bishop. Their personal integrity is on the line in this promise. On the other hand, diocesan priests can testify that there is great freedom to be creative in the priesthood.
Bishops rely on priests along with the laity to suggest necessary pastoral initiatives.
A bishop also tries to match his priests with the work that needs to be done. Ordinarily, a priests ends up doing work for which he is well enough suited. The bottom line, however, is service, not pleasing oneself. It is not because they despise marriage or family life, as many priests would tell you. And so they make a promise of celibacy before they are ordained.