Taoiseach Bertie Ahern said he always defended public servants who made administrative errors in Government departments.
He was responding to a question from Fine Gael leader Enda Kenny on a senior official's failure to tell Minister for Transport Noel Dempsey about Aer Lingus's plans to end the Shannon-Heathrow service.
Mr Kenny that the Minister had said he was not notified. "That is not efficiency."
Mr Ahern said there were times something was not brought to the attention of all the relevant people, whether it was the Taoiseach, a Minister, a Minister of State or a public servant.
"Reports are done in such cases. Every department is complex and deals with a huge range of issue. I always defend those involved in such matters."
He said when walking the corridor from his office in Government Buildings to the Dáil Chamber he was stopped by numerous officials and asked for directions on issues such as Cabinet matters or meetings in Northern Ireland or Europe. He gave instant decisions.
"My decisions are then recorded in complex e-mails, which I might not recognise or remember in two months' time.
"I find it interesting to see how others having difficulty in remembering something that happened a month ago, while eminent people in another location expect me to remember with certainty what happened 17 years ago. Perhaps they credit me with more intelligence than everyone else."
Mr Kenny interjected: "That is the $50,000 question."
Mr Ahern replied: "I do not think so. I am meant to remember everything. When decisions are made in that manner, some things can go wrong.
"The civil service does its best to avoid these situations, but sometimes things go wrong. There is no question of people not doing their very best."
Replying to other Opposition questions, Mr Ahern defended the benchmarking process, and revealed that increases under the scheme in his department last year cost €800,000.
He said under the terms of Sustaining Progress the pay increases recommended by the benchmarking body were conditional on real modernisation and flexibility.
He said the performance verification group had concluded that the progress achieved warranted the payment to the grades concerned in the Department of the Taoiseach
