There are two ways to be socially acceptable.
Only do things that are acceptable to those surrounding you; or only surround yourself with people who think the things you do are acceptable.
Naturally, I follow the second. Anyone who knows me can tell you that I'm the obnoxious sort that does pretty much what ever she wants.
I'm too imperfect to pretend that I am. I'm prideful, and insecure. I'm immature, and crude. I'm all those things your mother told you not to be. In fact, everyone is. We're all prideful, we're all insecure. We're all immature, and we all have a crude side. Some of us are better at pretending we aren't than others are. It's an art, the art of perfection; the art of pretending you aren't really human.
In his book Mere Christianity, C.S. Lewis tells us that pride is an ultimate sin, the one thing that no Christian would ever admit to. As much as I love C.S. Lewis, I think that's incredibly foolish. Pride is one of the basic things that we as humans live on. It's the greatest motivator we have. Of course, it can lead to a lot of bad things - overly large doses of pride have caused a lot of the biggest disasters the world has faced.
However, in moderate amounts, pride is good for us. We all take pride in some things, and that pride encourages us to take them somewhere. Pride in skills at math, pride in playing hockey. Pride in achievement. And then there's the kind of pride that encourages others to go places - pride in someone else's accomplishments will be beneficial to them, too.
I disagree with the idea of modesty - and by this, I mean false modesty. (In reality, there isn't much real modesty around. If you are confident in yourself and don't feel the need to share your accomplishments, that's great.) Maybe because I can't really grasp it. It doesn't make sense to me to pretend to be any less than you are. I think that modesty is just a defense against jealousy - if you pretend you don't have anything to be jealous of, no one will be jealous of you.
Psshaaw. If other people struggle with jealousy, that is their problem. Part of growing up is learning to appreciate other people's attributes without letting yourself feel lesser. I'm surrounded by people who are smarter than me, more talented, more creative, harder workers... and yes, some days I feel really insecure. However, if you don't feel good enough, the best solution is to IMPROVE YOURSELF! I'm jealous of my friends' talents, but rather then letting th at be a negative aspect to our relationship, I work on my own talents.
I think we, as humans, focus too much on not being human. To be human is to have both good traits and bad traits. I'm not saying it's okay to let the bad ones take over your life; everything in moderation. However, it's not bad to be human! Be kind, but take time to be selfish. There's nothing wrong with taking care of yourself. Appreciate others' work, but take pride in your own. Be mature, but don't be afraid to let loose (and make that really bad sexual joke you've been thinking but are too afraid to say) every now and then. Be gentle but stand up for yourself.
No one is flawless. We like to pretend we are, or at least have the potential to be - but we don't.
Perfection is being imperfect, and loving it.