The skills a character can have would normally be restricted to a subset of the entire skill list in the game rules, based on what skills would be reasonable for the character to actually know.

This is why it's vitally important for your private detective to be an active member of the Society for Creative Anachronism, or for your wandering minstrel to have frequent hyper-realistic visions of men made of metal and people travelling to the stars in giant galleons.

Transcript

[SFX]: roll
Adam: 3. Well I guess that's fail.
GM: You don't see any trace of R2. And it's dark out.
Adam: Damn. We'll have to track him down in the morning.
C-3PO: What skills do you have? They'll be on your sheet.
Adam: Um... Armoury, Climbing, Hunting, Piloting, Riding, Shooting, Stealth, Survival: Desert, Survival: Forest, Survival: Snow—
Leia: Snow?
Adam: —Survival: Swamp, Swimming, and Tracking.
C-3PO: There you go.
Leia: How the heck do you get snow skills on a desert planet?
Adam: Er... It gets cold at night?
Leia: Not that cold.
C-3PO: In the freezer?
Adam: Ha ha, yeah, right. My parents make me live in the freezer for space-Lent every year. I build igloos.
C-3PO: Cool!