> That being said there are better ways of phrasing it than "this isn't my job". Saying something along the lines of "if I do that I won't have time to finish X by next Tuesday as I promised. It might be worth checking with Dave and his team if they have someone who can work on it. Otherwise I'll be happy to do it, as long as you're OK with pushing X back a week".

Your whole comment was spot-on, but this part in particular resonated with me.

Over my relatively short career, there have been waves of being overloaded and then feeling like I had a handle on things. Whenever it’s been the latter, I can usually trace it back to being consistent with giving folks the simple cause and effect of what they’re asking of me. It helps that I happen to enjoy basically all the work (even remotely) relevant to my role, so when someone asks me for something (for perhaps the 10th time that day), I kindly say that I’d be more than happy to do that “..but this is what that will mean for the first 9 things you asked me for today..”.

I’ve found this to be an organic, effective way of filtering out priorities from background noise without creating that alienation between you and your boss/coworkers that was mentioned further up.