Glad to read you found my post helpful DoS.
So, arigato, back to the example of a house. How big is the chance that someone rings your doorbell with the intention of doing bad things to your house? The chances of someone doing harm to your computer are about the same. Besides, it greatly depends on what you are doing with your computer.
If you are doing things online that other people do not like then the chances are those other people might get nasty. Either way, as it was suggested before - a locked door will keep most hackers out. Install a
decent firewall!
Finally, the thought that the internet is full of people who want to do nothing but harm your computer is fictive. The thought that more than 0.01% of the people online even
know how to do harm to your computer is quite silly also.