Yes I believe that. In everything that happens to us in life even the bad we need to look back and see what positive lesson or message is ther for us to learn. If you take your time you will most likely find it.
not all the time. but they do happen sometimes. we learn from our mistakes. through the mistakes (which is something bad), we learn to be stronger and wiser so not to commit the same mistake again in the future(which is something good).