Probably what he meant was that if you write this:
then that catch block will catch not only exceptions that your code throws, but also exceptions due to unrecoverable problems like OutOfMemoryError, StackOverflowError, and worse. These are all subclasses of Error, which is one of two subclasses of Throwable (the other one is Exception). In general, if you want to catch generic problems, use Exception; then things that are meant to be fatal, will be.
This isn't to say that
you should never catch Throwable -- but that you should account for all the possibilities when you do so.