[Traveller] Does Luck have to be PSI?

[adimar]

I'm continuing in fashioning my gurps traveller character, and would like him to have the Extraordinary Lucky advantage.
I also like the idea of explaining it as an unconscious use of a PSI power. (this explanation is purely fluff).

I have two questions:
1) Do I also need to take the unusual background(PSI)?
The same can be asked about a character with Danger Sense (Unconscious use of ESP) etc...
2) Does that character have a Secret? (I mean, he's a psi but he doesn't know it, make active use of it or train it)

Best regards
Adi