Yes! There's lots here, but, the "eight worldly dhammas" answers this question as well. The danger of conceit: "I am someone important!" That's where every dictator gets lost. That's where every crazy politician gets lost. That's where teachers can get lost. That's where individual people can get lost.
If you get too conceited about your statistics, what you've done: "I'm a ten-year-meditator, I've done this and that", you can get lost. We've had assistants go to other centers and tell them that they're an assistant of ours "Oh," all of a sudden, they get treated very special. Very unfortunately, it went to one assistant's head and their ego went berserk. They started believing they were far beyond us, because they got treated so lovingly by other people, because of their statistics. Conceit's very dangerous.
There are other parts of this question, "Can you please talk about the danger of conceit":
Second part: "How to recognize it in ourselves?";
Third part: "How to let it go, once we see we are under it's influence?"
"How to recognize it?" We have a lot of thoughts about "me". The basic definition of conceit is: "I am". "I am this", but also includes, "I am not that". It's simply an "I am", the thought of conceit.
"I am a man", now that's a pretty neutral type of conceit; "I am an American", that can go one way or the other, can't it? So, to recognize it in ourselves, we ask how many of our thoughts are: "I am," type thoughts.
When you think of the mental noting practice, and when you think of the Compassion/Lovingkindness meditation as well, some people get confused about how to use either one. I'll give an example where conceit comes in. We teach with the mental noting, just to note the reality of what's happening: "hearing, hearing"; "thinking, thinking"; "wandering, wandering". Those are words that simply apply to what's happening in the mind. Some people use the mental noting: "I'm wandering; I'm thinking; I'm doing this..." That's wrong, we don't want the "I" there.
With the Compassion/Lovingkindness meditation, we teach to use a phrase that begins with, "May So and so - ; May So and so - " i.e., just a wish for that person. We discovered that one old student was using a phrase, "I wish So and so - ";"I wish So and so - ", but we don't teach that. This particular meditator does have a lot of conceit problems within their practice, and there it was, right in their meditation wording. So, the "I am," is the way to recognize conceit.
When you're walking to the dining hall, and you know you're just walking; when you're grabbing your plates, you know you're just grabbing plates; putting food on; when you're just eating - when you're just doing, (and especially if you do use the mental noting with it) when you're just doing, there's no "I".
Shut your eyes for a moment and take a good breath in and out.
Now you tell me: was that a man's breath or a woman's breath? Was it an old person's breath, or a young person's breath? There's no such thing there. It's just a breath. So we have to drop these "I am," thoughts as much as possible to get rid of conceit.
"How to let go of it once we see we're under it's influence?" To reflect on the Dukkha of conceit is a very healthy way to get rid of it. To reflect on the dangers of it, not just the Dukkha of it, but also what it's going to produce in the future. You can also reflect on people you've met, who are very, very conceited. Bring them to mind. Remember how they acted, remember what they did when they were acting very conceited. By remembering how other people act who are conceited, then you might be able to see it more easily with in yourself, when it affects you.