I have tried in a website which calculates how much is needed to crack it (the RAR) in that website. It says to me that even with 100.000 PC with 500.000 passwords per seconds it needs about 12.000 years and a bit more to crack. I think this is safe, as the computers there are cluster computers and not just 100.000 pc connected to each others.
12.000 years is off, because you use words from English language. Hackers do not need to try every combination like abCD$!. It also assumes your computer is secure and you don't have any programs that spy on you. Even (state-owned) computers without internet can be hacked, like that system in Iran.
A good password makes it harder to access your computer, but not impossible.
It is true, There is no safe password because there many tools for cracking algo. But a 13 characters is a very difficult password based on my experience and even a pro hacker without a clue about on your personal info will not gonna make it within a day.