I encountered a video on YouTube named “Fools Rush In, Joker’s philosophy” (link)
I google’d Fools Rush In but I could not find anything relevant. Or is it rather like that there is something relevant to the Joker and I am failing to notice it?
Thank you :):)
There’s an old expression “Fools rush in where angels fear to tread”. The title is presumably a reference to that.
I always say, if you’re going someplace where angels fear to tread, rushing is probably the wise way to do it. 
Yeah, “if.” The key word is “in.” You should be rushing out.
And why should it matter if an angel fears to tread someplace, anyway? They have wings-- Just keep flying, or hover a bit above the surface. No treading necessary.