Keane, who will lead his side into a real six-pointer against Premier League basement boys Derby on Saturday, said: "You get flashbacks all the time.
"I look back on my career and probably there were five or six major setbacks I had, and not a day goes by when they do not come back into my head.
"That will happen until the day I die - and last weekend is certainly one of them, and rightly so.
"It is always the setbacks you remember, unfortunately, it is never the good times."
Keane was involved in a series of high-profile disappointments and incidents during his playing career, including his infamous bust-ups with Republic boss Mick McCarthy and Manchester City's Alf-Inge Haaland.
However, he smiled when asked about the particular memories which come flooding back.
He said: "Let's not go there and open a can of worms. I'd forgotten about them until you asked me.
"There were different setbacks - sendings-off, injuries, whatever, club situations, country situations - there would be five or six things that would always stick in your mind.
"You would hope to keep that list fairly short, but last weekend has added another one.