This quote is from Cardinal Ratzinger's thoughts on his job as head of the CDF. It wasn't really what he would have preferred to do:
For me [becoming Perfect of the Congregation for the Faith] the cost was that I couldn’t do full time what I had envisaged for myself, namely really contributing my thinking and speaking to the great intellectual conversation of our time, by developing an opus of my own. I had to descend to the little and various things pertaining to factual conflicts and events. I had to leave aside a great part of what would interest me and simply serve and to accept that as my task.