Here are a few things that I have had to remind myself of. Hopefully they will help you as well.
- Don't take it personally. In most cases, your student didn't mean to disappoint you. He/she probably didn't do it out of spite or maliciously. The disappointment you are feeling was not done by the student to hurt you. He/she probably didn't even have you in mind when he did it.
- Remember, he is just a student. Even when your student does the stupidest thing on the planet, you need to remember that he is just a student. You and I both did some really idiotic things. I once jumped up and down on a table in the church lobby singing "Dude Looks Like a Lady" by Aerosmith. I also blew up some mailboxes with firecrackers after being dropped off at a friend's house following a youth group event. Did I disappoint my youth pastor? Absolutely, but he didn't hold a grudge because I was only a student. Remember that when your students are doing similar things.
- Continue to love your student. There are going to be times when the disappointment you are feeling is going to run deep. When you are called to the hospital in the middle of the night because one of your students has alcohol poisoning. When you find out that one of your students is expecting a baby. When a student lies to your face about what you saw on her Facebook page. When this happens, remember that you are there to love your students, just like Christ loved you. Enough said.
I am finding out that being a youth pastor is one of the most challenging and enjoyable professions there is. But just like any profession, there will be dark days, especially when that darkness is brought on by one of your students. Bathe it in prayer and remember what you have been called to do.