Astrophysicist here. Yes, space is crazy, but interesting things to keep in mind:
- The size of a star is determined by something called the photosphere. With those extremely massive stars, you can be hundreds of millions of kilometres "inside" and not yet know it.
- Similar story with supermassive black holes, from the perspective of an astronaut falling in, they wouldn't really be able to tell when they cross the horizon because the tidal forces there are very small (they will inevitably fall towards the centre and get spaghettified at some point)
See my response below to Captain Aggravated about how dilute those large stars are.
It's an interesting question whether anybody would actually feel spaghettification ๐ I actually don't know. You can use physics to calculate the proper time derivative of the tidal forces, but you need biology to define the start (and end...) of the process. My intuition says that it probably happens too fast, so once the tidal forces are strong enough to be perceptible, they grow strong enough to rip you apart before you realize (again, just a hunch).