Random Attack

Sorry, but that's utter bollocks. No martial art prepares for that kind of attack. You'd have to make sure you spot everyone, and everything they could do to you, and that's not really possible when you're just cycling along.

I know the "self defense" mindset, I can hear that kindo stuff in my wing chun classes and so on.
Do you want to be the kind of person that never goes out, never sits in a restaurant unless there's a wall in the back etc? IMHO just boils down to plain paranoia.

Sure, there is gut feeling, not looking like a victim and all that. But a sucker punch while cycling past? How the fuck are you anticipating that? Sounds to me like anticipating getting struck by lightning.

+1
There's always someone that will say something like that after you've been attacked.
I guess they're trying to convince themselves it won't happen to them or that it can somehow be prevented.
By definition you cannot predict a random attack.