Not because you never had trouble with it before means it will never give you trouble. When dealing with electronics they can break all of a sudden without a warning. Software can break too, like Windows problems, viruses, etc...
By the way Norton isn't a really good anti-virus it's more expensive because you pay for the name, and it only does an average job compared to others. There are many other security suites now that can do a much better job like: Avira, BitDefender, Kaspersky, Avast, etc...