Come, come, come. Let us talk about something real brief.
People that know they have actual flaws in our character - you know; the people that are chronic latecomers, the people that are rude, the ones that lose their temper like they get paid for it. The people that have a terrible attitude to work. The people that don't care for personal hygiene. The ones that look like they're constantly buying clothes they want to grow into.
The same people will then turn around to say and I quote; "that's just who I am." These people will also make you feel bad for it too, talking about, "if you don't like me for me, we can't be friends." Same people that say things like 'I don't like people' or 'people are stupid'.
First of all... uh, okay.
From "Boys will be boys" to "that's just how they are", we've really normalized bad behaviour to something that is part of life. In some people's view, it is okay to not address a flaw so glaringly obvious as long as it has been part of you character for a long time.
It is important to note than these are formative years that will set up the rest of our lives. Whatever you get into your psyche will take even longer to remove or adjust. If you are abrasive to your own growth now, imagine what it will be like as you get a lot older.
Think of those REALLY wrong things grandparents say;
The ones that make you go ... oh my God! Donald Sterling for example.
If you don't fix yourself now that'll be you.
Posterity aside, the here and now needs to be addressed as well. What does it say about you if you know something is wrong with you but refuse to take care of it? It is one thing to have a bad trait that needs addressing, it is another to willfully ignore it. Like you actually, actually, know there is something that you've been told is an issue and you've chosen to let it remain unaddressed. Okay then.
In the context of character, it takes one really bad trait to ruin a host of your amazing strengths. The thing about human nature is the consistency of it. A terrible character trait is death by a thousand cuts. It starts off like little scratches here and there. By the time a bad trait about you has been noticed or worse yet told to you, it NEEDS to be helped.
Help yourself! Do something about it!
As we get older, traits and repeated choices set into our character. These become the foundations of the things we do. As your character goes, people associate you accordingly. Don't become associated with trash.