I've never had to use my guns. Although one has come out of the safe in a very tense situation. It was not used or even known about, but it was ready.
It turns out that if you have a gun, and you get attacked, you can actually get that gun out and use it if needed against the attacker. Even just attempting to use can stop the attacker. Even just making a noise with it, like a pump action or chambering a round, can prevent an attack. Even just announcing it can do so.
Here's how a gun can protect you. Someone is attacking you, and you shoot them. That's just one example scenario.
It turns out that you can shoot someone who is trying to rape or murder you and that can actually prevent them from doing it.
I can get my guns faster than you think.
Actually criminals prefer to find targets that are unarmed. Crime benefits from an imbalance of the ability to produce force. Criminals don't look for situations where they're on equal footing with someone they want to victimize. It's hard to get much leverage over someone with even a small gun, no matter how big yours is.
Our non-gun crime is pretty staggering here.
Edit:
I just spent some time on youtube looking for good 911 calls of people who shot intruders while on 911. There are some great examples and I just can't post them. They're too... disturbing. I just watched home surveillance camera of a guy break through a door carrying a machete and get shot after entry. Uh... it's not fun to watch. If you care, you can google tons of examples of people saving their lives and the lives of their family.