A new research has indicated that fun-loving cheeky monkeys may give the impression that they are not burdened by much, but that is not true.
It suggested that they do in fact feel the same regrets as we do - at least when they are playing the game rock-paper-scissors.
After first being taught the childhood pastime, test animals picked the winning symbol from the previous round, suggesting they rued not choosing it earlier.
By examining their brain activity, scientists from Yale University, Connecticut, were able to identify which parts deal with reason and the emotional sides of regret.
Researchers Daeyeol Lee and Hiroshi Abe designed the experiment so that they could understand the neural processes underlying regret.
''Regret serves us well most of the time, by helping us recognise choices that lead to bad outcomes," the Daily Mail quoted Lee as saying.
''But sometimes regret can be very damaging...Our brain is wired to run these hypothetical simulations all the time.
"If you try to learn only from the actual outcomes of your own experience, this represents only a tiny fraction of information you can get from your world," added Lee.
Lee and Abe's experiment involved rhesus monkeys receiving a small reward for trying and a bigger one for winning the game in which rock trumps scissors, paper trumps rock and scissors trump paper.
They then recorded the primates' neuronal activity.
Two things quickly became evident. First, the monkeys were aware not just of when they went wrong, but also how.
This indicates that the monkeys can imagine alternative outcomes and act on that knowledge, but not necessarily regret.
However, in the second set of findings, the animals' neuronal activity in these situations revealed they were experiencing both rational and emotional forms of regret in the prefrontal cortices of their brains.
They saw the memory centres of the brain were relaying information to the monkeys about the preferred outcome, while the emotion centres fired off in response to this regrettable outcome.
The study has been published in the journal Neuron.