I'm afraid of space.
The thought of bouncing around in a spacesuit outside a shuttle or space station scares the shit out of me, knowing that the slightest nudge could send me floating off into nothing, leaving me to decide to either let my air run out or just say fuck it and open my faceplate. No thanks, no way.
And space is fucking huge, so it's not like I'd be floating past Jupiter in an hour and get to see it up close before punching out. That's one thing that movies almost always get wrong: the obscene vastness of space. In the movies, interstellar travelers are always passing really gorgeous, epic cosmic shit up close, marveling at it through the portholes or from some ridiculously swanky viewing platform. That's not how it works. You're light-years away. You try and get as close as they do in the movies, and you die. Space isn't a scenic getaway; it's an infinite expanse of vacuum, gravitational density, and heat death, and it's waiting to kill you.