Whether you wish to be a hacker who is interested in hacking wireless network, web app, database; cracking password, software....; or want to engage in cyber security related works in the future, Offensive Security's Kali Linux (a penetration testing OS) should be always your main "battlefield" and "experimental field".
Today, wireless network has got very extensive application because of its convenient use and structure, and will eventually cover every corner on the earth, I believe. But due to its broadcast form of data transmission in a wireless network environment, that will inevitably lead to security issues. Of course we can ensure data security by setting different encryption methods in a wireless router, but some loopholes of Wi-Fi network or the router itself can often make every trained hacker be able to crack/hack it.
Kali Linux is a comprehensive platform for penetration test and security audit, has a wide range of usages in the information security industry. It comes with many advanced tools that can be used to identify the target and detect, exploit the vulnerabilities that have not been discovered in the target network.