"former mistakes" is a correct and usable phrase in written English.
It is often used to refer to mistakes that were made in the past or earlier in a sequence of events. Example: The company's new CEO is determined to learn from former mistakes and lead the company in a more successful direction.
The first section chronicles the break-up of the couple, and a sorrowful tone is established as she laments her former mistakes.
The vast majority of time, when I trusted my gut, the core of all my learnings (especially from my former mistakes), I was much more at peace with myself and more proud of the outcome, even if it wasn't perfect.
A systematic review which included literature from the Netherlands, Belgium and the UK, among other countries, showed that barriers to GP-patient communication in palliative care include the unavailability of a GP, reluctance by both patients and families and their doctors to discuss a 'bad' prognosis, and failure by GPs to discuss former mistakes.
The truth – which the Secret Service seems intent on reminding us – is that actual government agencies are made up of people who are perfectly capable of making terrible choices, terrible people who would rather not get into trouble, and those who would rather cover up the formers' mistakes than deal with the paperwork.
Jessee pinned much of his former behavior—"mistakes that haunt me until this day"—on drug addiction, a plague he says he shook at the beginning of the decade.
Despite the fact that some intend to return Egypt [to its former state], mistakes were made here before they happened there - vision is lacking....The regional scene in general, and particularly Egypt, seems weak in its solidarity with the Gazan ordeal.
Being the former, they mistook themselves for the latter.
"We would hope to be judged not by whether some former employees made mistakes but by what we're doing to make it right," Mr. Stickler said.
The former dictator admitted mistakes but apologized for nothing, and claimed that he had no bitterness toward his patrons turned conquerors.
The City Council speaker, Christine C. Quinn, said, "The question now is: Is he changing things to make sure he is learning from the mistakes?" Former Mayor Edward I. Koch, whose own third term was bruised by scandal, said Mr. Bloomberg needed to continue to speak frankly about his missteps.
He knows the former president made mistakes in his unsuccessful re-election bid; in an interview in 1994, he said that "the big lesson I learned in 1992 is that you can't rest on your laurels and hope the voters will elect you out of gratitude".
