Regrets: we all have them. While some may be relatively small, like spilling a secret you were supposed to keep, or that stupid butterfly tattoo you got when you were 18. Others can have serious, sometimes life-changing, repercussions.
There are mothers who have spoken about regretting having children and, conversely, those who desperately regret terminating a pregnancy or not starting a family sooner.
But while regrets may come in all shapes and sizes, it's our ability to deal with and move on from them that shapes our lives going forward. But how does one go about moving on from past mistakes?
"The first thing I think you need to recognise is that regret is one of those things that can go around and around in your head for the rest of your life but you can't change it. You can't go back," psychologist Bev Ernst told HuffPost Australia.
"So one of the best techniques to employ is CBT [cognitive behavioural therapy] to help you change your thinking around it.
"Another helpful technique is to practice mindfulness, which encourages you to live in the present moment.
"It's looking at those things you ruminate over but at the end of the day, understanding you can't actually change them. You need to acknowledge the things that have happened and take what you can from them. Learn from them. You don't have to ignore it completely -- in fact that's one of the worst things you can do -- but instead take what you can from the experience."
The best thing to do is to acknowledge that it's happening. Do some work on how it makes you feel when you think those thoughts.
According to Ernst, one of the main things about regret that people find so hard to deal with is the fact there's rarely a chance to right your wrongs. As such, it's very easy to get stuck in a rut where you're essentially obsessing about something you have no control over.
"That's why it's important to learn strategies to help you, and to be able to identify that's what you're doing," she said. "To be able to say, 'okay, I am dwelling in this self pity and regret mode, and that isn't helpful. I can't change things. Where do I want to go with this?'
"It's hard at the beginning, but it becomes much easier. Sometimes it can be very difficult for people to let go."
In fact, left unresolved, the consequences can be so grave Ernst says it can result in deteriorating emotional and mental health.
"It can definitely lead to depression. Depression and anxiety," Ernst said. "I'm not talking about superficial regrets -- we all have those -- but the deeper stuff about relationships or actions that have been taken or haven't been taken. We can sit there and dwell on it, and that can absolutely lead to depression and anxiety."
If you don't address the issue, Ernst said you could be at risk of becoming trapped in a negative cycle.
"When you have negative thoughts, what does that do? It makes you feel bad psychologically, but also physically it can be quite draining," she said. "Then you feel worse and have more negative thoughts. It's like a cycle, and it can lead people to do all sorts of things, like taking drugs as a way to stop feeling so bad.
"The best thing to do is to acknowledge that it's happening. Do some work on how it makes you feel when you think those thoughts.
"What is really damaging is when you sweep them under the rug. If you just try to ignore it, we know from lots of research it doesn't work, and eventually it will come back and bite you in the bum. It might not be straight away -- it might be five years, 15 years, 25 years -- but if you don't address it, it will come back.
"You can only do the ostrich thing for so long."
You don't want to be beating yourself about it for the rest of your life. It's about giving yourself a break and giving other people a break, too.
For anyone who is finding it difficult to address the issue, Ernst recommends seeking professional help.
"If people are really struggling with this, go and seek help," she said. "Just being in their own head isn't going to sort this out. Sometimes you need to have a professional give them a strategy to move forward and change the way they've been thinking.
"The potential consequences of unresolved regret can be huge. If you're feeling depressed about stuff you can't really change, it can even drive you to the point of suicide.
"You need to give yourself some compassion, learn some mindfulness techniques and coping strategies. You don't want to be beating yourself about it for the rest of your life. It's about giving yourself a break and giving other people a break, too.
"Otherwise it's all just wasted energy blocking you from other things, including being happy."