Your lucky never having a virus or having an intrusion attack on you computer , They are everywhere online - I was on BING, and I typed in search bar, Emperor Chair (gaming desk set up that's absolutely epic) then clicked on images , when I selected a picture of the item I was looking for my Norton security flashed up with a warning straight away that it has just stopped a high risk intrusion attack on my PC . The people who try to hack you will have an easy time if you got no protection and you wouldn't even know your infected.
even if you download a freebie , something is better than nothing ,it doesn't matter what security company you go with.
Personally I will gladly part with £20 a year to know I'm safe.