Obi-Wan lies to exaggerate his own importance because he needs Luke’s hero-worship. Obi-Wan says of Mos Eisley Spaceport, “You will never find a more wretched hive of scum and villainy.” He knows that Jabba’s hideout is right around the corner, and that it’s ten times worse than the cantina he drags Luke into. He just wants Luke to feel like he’s tagging along with a big man.

Obi-Wan probably uses these lies to cover a massive inferiority complex, which is why he makes that patently absurd statement to Vader: “If you strike me down, I shall become more powerful than you can possibly imagine.” The powers of Obi-Wan’s ghost voice are about as impressive as a C3P0 comlink. Obi-Wan’s feeble boast is merely the last utterance of an old man who can’t admit that he’s washed up.