When you write a program, ensure that you have a good framework being implemented to accomodate for unforeseen circumstances and unhandled conditions. Having unhandled exceptions lead to many problems. A few are:
- Unhandled exceptions left to the runtime actually are severe peformance penalty for the application
- It presents a very bad image of you in the eyes of your user.
For starting developers, I would always recommend that along with the minimum using directives, always have the first simple try catch statement and then appropriate exceptions being handled with care.