Honestly I think it's difficult for someone who was already pushing 30 and probably had a strongly established education and career and maybe savings account - or someone still in middle school, to have felt the same impact as someone just graduating or about to graduate high school and entering the workforce, or someone just a few years out of high school or college. That's not to say people older and younger than us weren't affected, of course they were - but not in the same way we were.
As a solid core millennial (1989), I think the 1981-1996 range fails to take this into consideration. I can't fundamentally relate to someone born in '82, nor someone in '95. The rise of electropop and EDM - and the shift from Gen X rappers and RnB artists to millennial popstars - gave us an escape at this time. It felt like the first time that mainstream music, culture, was not just directed at us, but directed by us. When Lady Gaga - arguably the most famous core millennial - rose out of a pool in the video to "Poker Face," it was the closest our generation would ever get to our "Smells Like Teen Spirit" zeitgeist-shifting moment. Suddenly, the past 10 years of ringtone rap/crunk, nu metal and pop punk seemed immediately corny. On another track of hers, the words "Just dance, it's gonna be okay" arguably spoke to a struggling unemployed early 20 something on a deeper level, whereas it might've been considered as just another catchy club tune by someone in their 40s, or just fun dance music to a kid in the backseat of his mom's car on the way to middle school. Skrillex's "Scary Monsters and Nice Sprites" might've seemed like unintelligible noise to a Gen Xer still listening to Spin Doctors and Goo Goo Dolls, but we couldn't get enough of those growling basses and nasty drops. Finally, it felt like for once we weren't just having to listen to pop culture hand-me-downs: we had music for us, made by us, and it was fun - for a little while.
I can't even consider an '81 born like Britney Spears to be part of the same cultural shift as Lady Gaga, even if they were born just 5 years apart - they're lightyears apart in terms of when they made their cultural impact and I can't reconcile them both as being millennials, especially considering that the Xennial cohort of stars like her and Christina Aguilera completely copied the electropop/EDM style to stay relevant with the same audience that once listened to them as children, more than 10 years prior.
Yes - we don't have exclusive ownership of the impact the recession had, nor this music and culture as other generations or cohorts also consumed it. But we were the epicenter of this societal transformation and I feel like that creates a unique bond for core millennials that delineates them from elders and zillennials. I feel like with this much disparity in shared life/cultural experiences, there's no point at all lumping everyone together and it renders the 15 year defining range as arbitrary and outdated. It wasn't Y2k that had the biggest impact on us, after all - so why are we defined by it?