Intruder can attack your box not only by using zero day exploit. They have many methods to do so. They can bypass IDS/IPS, Anti-virus, firewall and WAF. Please don't look them down or you may felt a great regret.
Intruder attacks home users for many reasons. Sometimes, they do that are not for stealing data or money.
How about intruder captures images from your webcam when your webcam is turned on.