"Obi-Wan is wise but he has not heart" - Anakin Skywalker
This always comes out on novels both legends and new canon and is strongly implied in Tcw so I believe it´s a character trait Anakin believes Obi-Wan has. In fact this belief from Anakin was quite common especially after AOTC and before ROTS.
There are a lot of reasons for Anakin to believe it, first of all, Obi-Wan tried his best to become an aloof Jedi master so Anakin would become the "perfect jedi chosen one" but Anakin came from a warm family and community so Obi-Wan´s aloofness was understood by Anakin as lack of affection which made him feel emotionally isolated during his years at the temple given Obi-Wan was his main caregiver but he hardly if ever showed him affection the way his mother or his friends at Tatooine did, so Anakin grew up to greatly respect Obi-Wan´s force habilities but learned not to expect him to cover or even understand his emotional needs.
The interesting part is that he still loved him and respected him as a father and didn´t try to change this part of his personality, Obi-Wan was Obi-Wan and Anakin would not try to change him.
This got to a breaking point after Shmi died, because given Obi-Wan lack of wory over Anakin´s mother well being and subsequent death, this didn´t made Anakin love or respect Obi-Wan less but he stopped trusting him altogether and came to this conclusion, Obi-Wan is a wise Jedi Master but he doesn´t have a heart and Anakin could not change this.
This perception helps to explain why Anakin even tried to keep contact with Obi-Wan even after the whole Hardeen bussines in which Obi-Wan quite mercilessly used Anakin´s affection for one of his missions, Anakin forgave Obi-Wan because for him Obi-Wan was acting just like he was an aloof Jedi Master who cares for the mission and the order first and foremost and Anakin´s affection is a sacrificial character trait and comes secondary to this.
This also helps explain why Padme and Palpatine became Anakin´s primary confidants and while he still cared for Obi-Wan, he knew he could not trust him with his heart or his affection of his toughts, Anakin wasn´t even sure Obi-Wan would even care.
The ironic thing is that this change in Anakin made Obi-Wan less neurotic about being the perfect Jedi and actually try to become comrades and fellow Jedi once Anakin stopped asking him to play a role he didn´t ever want to play but just when Obi-Wan tought Anakin was alright, it all came down, because this kind of misunderstandings have consequences.
Obi-Wan and Anakin loved each other but never truly understood each other.
