[quote=@Extra]
<Snipped quote by Etcetera>

My father tells me to never regret anything. Ever. No matter how bad it is. What's your opinion on that.
[/quote]

Well, I think you should regret things to a degree. Say you committed genocide of a whole planet of creatures because you thought they were all insanely evil, but then you found out that they were all peaceful and moral and good. Wouldn't you regret that?