Some days it just gets to you...

So I work in a job that I can pretty much count on being lied to on a regular basis. Knowing that getting lied to is almost a part of my job description makes it easier to swallow, but it doesn't always go down smoothe. I have a girl that is days from her 18th birthday and I told her specifically not to do something today, and found out about an hour ago that she did it and then when I was talking to her about it pretty much lied right to my face. When I found out at first I was really angry, but then it made me sad cause I just wished that she used her integrity when given the chance...somedays it just gets to you...