Taking Criticism
This is very important to improving your work to a better standard and shows a great level of confidence.
The problem in some cases is that some people listen to the advice given and dont actually follow it. This is just going to get you a bad reputation with people around you and will not make the difference to your work that it needs.
Although that person may of made some great points about the parts of your work that are good. You also need to understand the things they say about the bad parts. This is the key to improving and developing your work.
The problem occurs when work is criticised about the bad and not the good. You must always have something good to say about work, not just bad. This can just lead to people getting demoralised and that wont help them at all.
Also on a personal level when you see that happening to someone, it can be fairly annoying as well.
Think then speak, cya next time.