According to Wikipedia, the expression "a curate's egg" originally meant something that is partly good and partly bad, but as a result is entirely spoilt. The phrase derives from a cartoon entitled "True Humility" originally published in Punch on 9 November 1895, depicting a timid-looking curate taking breakfast in his bishop's house. The bishop says, "I'm afraid you've got a bad egg, Mr Jones", to which the curate replies, "Oh, no, my Lord, I assure you that parts of it are excellent!"
The book, which is a collection of anecdotes from various probationer ministers concerning their early years in ministry, is aptly titled in that contrary to the idealistic view of ministry held by many candidates (myself included until fairly recently), many a "rude awakening" lies in store for the unwary probationer. The female probationers, in particular, seem to have a rough time of it, citing ongoing battles against prejudice towards female clergy - not only from members of the congregation, but (sadly) mainly from their male colleagues in ministry.
There are however some amusing anecdotes, particularly where probationers make a hash of things. I can particularly identify with the young curate who got the words of one of the liturgies mixed up, as one day (to my acute embarrassment) I got two of the lines of the Lord's Prayer switched around. Somehow I never seem to have this problem when singing it - maybe because we tend to sing it a lot slower, perhaps, thereby allowing my brain to keep up?
Going back to the title of the book, the original interpretation of the expression seemed to be that an egg cannot be "artly" bad, any more than a woman cannot be a "little bit" pregnant! However, the modern meaning is more along the lines that the "excellent" parts of the egg compensate enough for the "bad" parts to render complaints inappropriate. I would like to think that in ministry (as in all walks of life), the "excellent" parts more than compensate for the occasional "bad egg", and this view is reflected in the book.
Certainly none of the contributors thereto felt that ministry was so "bad" that they would rather do something else, although one or two needed a change of station in order to move forward.
The most gratifying part of the book for me was the realisation that ministers make as many mistakes as "ordinary" people do - a huge relief for me, given the number of mistakes that I have made in the course of what was actually quite a successful career in accounting and financial management. I will no doubt make many more during the course of my ministry, and I pray that, like in many of the anecdotes contained in the book, the "powers that be" to whom I will serve under in the Methodist Church will show understanding, care, and the occasional "flat hand to the side of my head" as I discover how to fulfil this awesome call that God has placed on my life to minister in His Name.
"Curate's Egg" is apparently out of print, although Amazon.co.uk does seem to be able to source some second-hand copies.