Domain knowledge is just useful in that particular domain unless you distill down general things into something you can carry forward. You cannot carry over skills from Call of Duty over to Starcraft, other than maybe, teamwork makes the dreamwork in multiplayer (this you can distill out). Once you leave a domain (the front lines), you will never be as in-tune as the people in it right now. I'm at peace with leaving domain-specific knowledge wherever I left it, because trying to bring over non-distilled concepts to new domains is a forced attempt at feigning experience. It's one of the problems with much of leadership, they ride on carrying over domain-knowledge from another domain when in reality they are total newbies in the new domain (ego does not allow you leave something behind, it wants to aggrandize you at every step).

However, if you are simultaneously involved in multiple domains, this is when the venn-diagram works its magic. The person with five different interests and professions is in a magical envious place of being able to touch the "overlap". I can see someone arguing that this does not have to happen in real time, that if you can simply remember everything, then you are always in this magical place.

Well one thing you just filter out a lot of noise. There's always a new hot paper or thing being marketed at you, but you learn what "new things" actually matter. And just have JOMO (Joy of Missing Out) on 90% of what's out there.