Because they are so knowledgeable, they normally have the perfect retort for any biting comment that is directed their way. Be careful what you say to them unless you are ready to get a sometimes sarcastic and quite often poignant answer. This is not normally done to offend, it’s just a gut reaction that they don’t always control.
The problem is that they usually hit the bullseye and go for your weak points. Because of this, they can sometimes make you feel bad about yourself, but bear in mind that was probably not the intention. The main reason for this is that they are pretty observant of the world around them and they tend to analyze every little thing they see.
Of course, with this comes a good side and a bad one. The positive part is that it makes them find a multitude of solutions for every problem. This helps them to be able to have a piece of advice for everyone around them whenever they get asked a question.
But, as with anything in life, this also has a negative side. Overanalyzing is always a risk, something that potentially will happen to a Ravenclaw more than any other person. They do this not only with others, but also with themselves, so sometimes they may get upset without any apparent reason.
If you are with them, try to make them see that things are not as bad as they may seem. Maybe they have overblown something out of proportion. Like, lets imagine you have a Ravenclaw girlfriend/boyfriend and you may have to cut a date short to meet with one of your friends. It is possible they start thinking about every encounter you have had with your friend and compare it with your time with them. Aaaand maybe then they get quite angry at you when you don’t seem to find a good reason for it. Does it ring a bell?