Still, I’d say that Booth has had a pretty complete journey on the series.
Even if David Boreanaz does have a regret or two, he can be proud that he crafted such a popular and long-lasting character.
We may never have gotten into everything that made Booth who he is, as David Boreanaz said, but he went through a lot of character development that had nothing to do with his props.
Evidently, there was somehow never room or the right time to delve into some of the background details about Booth.