Originally posted by: Go-Mer-Tonic
I realize he was fleshing a lot of this out as he went, but I think in the end it makes better sense that one would expect given that fact.

Given that he had over fifteen years to "flesh it out," it should've made perfect sense.

I don't think that Yoda and Obi-Wan taught Anakin how to retain his identity, he did that on his own when he gave his life to save his son and for the greater good of all beings in the galaxy.

Per RotS, the maintenance of identity is supposed to be a skill, a technique -- not something that is intuitively acquired solely by the good nature of your actions. If giving your life for the greater good of all beings in the galaxy* is enough to make one a ghost, then we should've seen a spectral Jek Porkins flying at Hoth and Endor.

I think the intention is that Yoda and Obi-Wan were able to help Anakin become one with the Force before he actually expired. He loses consciousness in front of Luke, but off camera, before he actually dies, Obi-Wan and Anakin assist him in becoming one with the Force.

Maybe he swoons in front of Luke, then wakes up in the shuttle and tells Luke the secret of a perfect chilled blue milk. But before he can tell Luke what aerosolized blue milk will do to Yuuzhan Vong, Yoda and Obi-wan show up and insist on giving Anakin a two-hour lecture, followed by an hour of practical work. This lecture is so interesting, both Anakin and Luke forget that the former is slowly dying. Anakin eventually drowns from the fluid collecting in his lungs, a painful and frightening death -- and the final revenge of the Jedi.

Or maybe he just became a ghost because that's what dead Jedi do, regardless of derivative products like the PT. (No matter their provenance, the PT is ultimately derivative of the OT.)

* NB: Vader gave his life for his son, not for all beings in the galaxy -- who he had been burning through at a prodigious rate for 20 years.