To mark the occasion, the IPA staff presented the M&C Saatchi Worldwide chief executive with a volume of his press coverage while in office.
And bang up to date it was too, even including his speech to the ISBA conference, which won him a case of Champagne for including the words "fuck" and "bollocks".
What's more, the IPA toilers were eager to remind their soon-to-be ex-leader of a few more painful episodes.
Including the time he turned up for the 2007 IPA Effectiveness Awards sporting a spectacular black eye. Some suggested it might be the result of the kick-boxing he took up after quitting his 30-a-day smoking habit. Hmm.
Will MacLennan's successor, Tim Duffy, prove such media fodder. Diary fears not, but M&C staff appear curiously relieved.