I have got a few examples::
- For instance when someone buys something and it turns out that it wasn't worth it, and this person tries to convince himself that he made a good choice or that the product he bought is actually worth it (he cannot accept that he lost money in that process). That might be at the cinema when the movie is bad and you stay until the end because you've paid for it.
- The other example is when someone made something which is likely to end badly, but the fact he began to follow this way lets him prefer to make an error later than go back on it immediately.
It seems to me that both are the same. I learnt the term for this phenomenon in a philo/psycho course at school a few years ago, I think the term is similar to "heuristic of loss", or maybe "bias of loss", but my search engine doesn't know that, so it is likely to be something else. It is possible that I mix up terms and concepts.