WARNING! Really convoluted fanwankery coming…
Yoda escapes to Degobah after ROTS. Yoda knows, or at least guesses, that someday that one of the twins will come to Degobah in search of guidance. Also knowing that they won’t be able to go through the whole paduon (sp?) experience, he uses his massive force powers to create a cave which will drive home the lesson “Beware of the Dark Side”.
Now you know.
And knowing is half the battle.
I forgive Owen, since most of those protocol droids look alike, I was wondering how come Obi-wan doesn’t reconize R2-D2 in Star Wars, or claims he has never owned a droid (he had one in AOTC).
My theory: he did seem to know his way around the Mos Eisley Cantina pretty well in Episode IV (sorry, I called it Episode 1 in my first post in this thread, I meant the first movie), and in ATOC he did tell Annikin, when they were in the bar, that he was getting a drink, so my guess is Obi-wan was an alcoholic, and was suffering from long term memory loss. 
Obi-wan is a liar. He lies to Luke alot. So why should his lie about owning a droid (technically he probaly didn’t own his flight droids.) be seen as a plot hole.
No forgetting there…that’s just a matter of either A) being out of whatever fuel is used, or b) his thruster thingies being damaged at some point between ROTS and ANH.
In TESB as Luke leaves Dagobah to help his friends, we hear something along the lines of:
OBI-WAN: He’s our only hope.
YODA: No. There is another.
This is the foreshadowing, I believe. And if I’m right (there’s always a chance), it opens up a new plot hole: Why didn’t Obi-Wan know there was “another”, since he was well aware of Leia?
Looked like plain ol’ motor oil to me. After his oil bath, you’d think flying around looking for Obi-Wan would’ve saved some time.
Although watching him burn a bunch of Jawas to death might have been a little rough.
“Peesacapord-nah…peesacapord-nah…See-pa-kah!!!”
“Beep-beep-beep!” ::Flies over them, napalming their robes, Jawas screaming and running flailing their arms as flumes of smoke escape from their hoods and arms::
After leaving senate planet, health coverage he lost.
I’ll take a stab at two of these:
In ESB, on Dagobah, as Luke is leaving, Obi Wan says “That boy was our last hope.” to which Yoda replies “No, there is another.”
At the end, as Luke holds on for dear life from the bottom of the cloud city, he calls out to Leia. We then cut to Leia, who quietly whispers Luke’s name and then tells Chewbacca that they need to turn around and that she knows where Luke is. She heard him call to her through the Force.
Yes, but the point of Luke going there was to turn Anakin back to the good side. In Luke’s mind, it was a rescue mission. Redeem his father and get the hell out of there before the rebels blow it to smithereens. He succeeded.
Obi Wan is about 38 years old in ROTS, making him about 57 or 58 in ANH. Alec Guiness was 62 or 63 I believe, so it’s not really a stretch.
I just looked it up and found out that Alec Guinness was 63 when the first Star Was released (Born in 1914 acording to the IMDB) suggesting Obi-wan was in his sixties.
Ewan however is in his early thirties which would make him only fifty-something at the begining of Ep. 4.
Once again. They must age quickly on Tatoonine.
obi-wan was 16 years older than anakin. y’all can do the math from there.
re yoda stating there is another.
leia was a rather busy senator and rebel leader. she had enough to do, no time for jedi training. obi-wan could be forgiven for overlooking her, i’m sure the conversation between him and yoda went on for a bit after that.
o-w: "yes there is another… but she is really busy, i don’t think she will drop everything to come to degobah and become a jedi.
yoda: “mmmmmmm, meditate on this i will.”
But consider that it was Leia who had been given the task of going to Tatooine in order to recruit Obi Wan into the fight. Perhaps Bail had decided it was time. If Leia had made it safely to Obi Wan’s residence, they probably would have gone and picked up Luke also, and then perhaps both of them would have been taken to Yoda to be trained.
RE:
Obi-Wan: That boy was our last hope.
Yoda: No. There is another.
My problem wasn’t with Obi-Wan not considering her, but with Yoda considering her. Why would Yoda think Leia was another when he considered Luke too old to begin the training at the same age?
Hell, they all thought Anakin “Yippee” Skywalker was too old.
Why didn’t RT tell C3P0 about their previous adventures? I recall them saying “erase this droids memory banks”, or this is a paraphrase.
It seems to me that Lucus makes worse and worse films as he goes along. I think that he snapped this streak with the last one. I will have to admit that this perception on my part is probably due to the fact that the plot line and visuals were taking us closer to the first movie.
Actually, I find the combination of hot desert air and lack of proper skin lotion to answer this one pretty nicely. 
“Your father wanted you to have this when you were old enough but your uncle wouldn’t allow it.” … “Your father’s lightsaber.”
I wasn’t paying attention. Did Obi-Wan pick up Anakin’s lightsaber?
Yes.
Although it was apparently Annakin’s fifth or sixth lightsaber. I think he bought them in twelve packs. Makes it not quite so special, now.
Not to mention that it’s been used to kill children. Kinda strips it of any honor.
There’s also the possibility the Jawas in ANH stripped the rockets off R2. We don’t see it, but it could happen offscreen.
After watching ESB again, I get the idea that Yoda is using the Age thing as an excuse. He tells Obi-wan that the boy has no patience and Obi-wan defends Luke say that he was the same way. Then Yoda immediatly says “Too Old”.
Yoda doesn’t want to be bothered with training, it seems. Perhaps he depressed after Anakin/Vader? Perhaps he’s just turning into a crotchity old man(whatever he is)? He did see a bit…loopy, when luke meets him in ESB. Particulary when he starts smacking R2 with his cane trying to grab the lamp.