The ending doesn't make sense? Spoilers Farseer & Tawny Man

[Syrocko]

I could never imagine someone being that apathetic about losing their best, closest childhood friend.

Hmm, you do have a point there, you'd think he'd act a little more gutted. I'd agree that Fitz probably doesn't fully accept the reality that the Fool doesn't intend to return. At the same time, he had already had his strong reaction earlier when the Fool removed their Skill link and told him he must leave. I would also argue that his bond with the Fool was never anything like his bond with Nighteyes. Not to say that he didn't love him as much, but Nighteyes was like his twin and his soul mate for many, many years. Their link was strong, they were nearly always together, they knew nearly everything about each other, heard each other's thoughts and experienced the world through each other's senses. Losing Nighteyes was quite literally losing a piece of himself. Fitz' Skill link with the Fool enabled them to merge completely when touching, but from any distance the bond seemed to be very weak indeed. Nonetheless, he does seem to accept having missed the Fool rather casually.

Going off on a slight tangent now, regarding the Fool being Fitz' childhood friend, I know it's a moot point in the end but I just wanted to point out that this isn't actually true. People keep saying this about him, and stranger still is the fact that even Fitz refers to him as such, but Fitz' real childhood friends were the street kids Molly, Kerry and Dirk, of whom only Molly retained a connection to him over the years. The first time Fitz and the Fool even speak to one another is when Fitz is 13, and during his teenage years the Fool only occasionally helps him or offers cryptic advice, but as often as not he infuriates or embarrasses Fitz, and Fitz is baffled by trying to figure out who he really is or what he wants (although I'm sure the Fool does already secretly love Fitz at this stage). It's only in AQ, when Fitz is a young adult that the two of them become closer friends after the Fool nurses him back to health from his arrow wound.