Maybe Eccleston didn’t believe the reboot of Doctor Who was actually going to work. Think about how little Patrick Stewart was prepared for Star Trek: The Next Generation for the first couple years. It’s just a TV show to some, most eventually grow to love the role, but some just don’t.
I think there’s been a tradition since TNG of giving the casts of the newer Treks a friendly warning/heads up of the craziness that’s about to enter their lives.
If they have any brains, they shouldn’t need a warning. Everyone not living under huge boulder knows what Star Trek is.
Yes, but nothing can prepare you for Trekkers showing up in costume in the audience at the Shakespeare play you’re in. That actually happened to Stewart.
Being aware of Trek as a tv show or film franchise does not mean you’ve looked deeply into the fandom. (A few were fans before being cast in later Trek incarnations, but most are just hard working actors.) Even Star Wars is just a movie to some folks.