Very important. Very serious.
I wasn't going to repeat myself, but then this happened:
Complete Breakfast by Trainwiz replaces Kellogg, the infamous mercenary who murdered your partner and left you to rot, with a packet of Kellogg's brand cereal. Choose from cornflakes, sugar bombs and Froot Loops.
"Why? I don't know," the creator writes.
Then there's The Mysterious B.I.G. by gyashaa, which replaces the Mysterious Stranger with the Notorious Bi.I.G. Of course it does.
One of my favourite genres of Fallout 4 mods is addressing the greatest mystery of the Commonwealth: why is everybody using gross old shit instead of making new things, or cleaning and fixing what they scavenge? Faction Underwear by PoliteRaider adds a pile of new decorative jocks to replace those rubbish old ones you've been wearing.
Hit the link above to see the rear view.
Finally (for now?), Sanctuary Hills Prewar Expansion Pack by tonicmole is a more substantial addition - a little chain of items and notes filling in some of the backstory on the Sole Survivor and their partner.
I wouldn't classify this as weird, and in fact consider it precisely the sort of thing Bethesda should have peppered the game with (only perhaps about other characters because role-playing et cetera), except for some reason the mod centres on the female character's love of Grognak the Barbarian.
It's very pure in its dedication to this theme, adding new Grognak clothing items. I guess it makes about as much sense as anything else.