When Anakin sees Obi-Wan standing at the door of Padme's ship, Hayden's performance beautifully captures the problem at hand: that Anakin knew Obi-Wan despite being a mentor, friend and brother in arms - would never approve of his absurd decisions. That's why McDiarmid dubbed the SW saga "Fathers and Sons". Obi-Wan is the rigid, strict parent that wants the best for Anakin, while Palps is the indulgent parent who supports Anakin's every move even when others deem it inappropriate.
Again, had Anakin been in his 40s in ROTS none of this would have worked. Vader only works when born of raw passion and feelings of insecurity and inadequacy in the eyes of the Jedi. A young Jedi lost. He matures into a calculating warrior as a Sith.