@Maala
When you get an amnesia from being so hardwitted, will you be able to communicate with your doctor, and will your muscles forget what you did for most of your life? I wonder...
In all seriousness, probably not depending on the severity. The amnesia most are familiar with from media is quite fictional. Case in poing: there are many examples of people walking up from a coma with some sort of brain trauma to lose the ability to speak their native language, but another language that they could never even speak - known as "Foreign language syndrome."
https://www.cnn.com/2016/10/24/health/teen-spanish-new-language-trnd/index.html
That's just a mild example. More than likely this dude would be quite fucked by having language issues and also not remembering years of martial arts.