Anyway, David was very insightful. Compared to Millennials, Xers were more independent from their parents when they were in their 20s and more dependent on their friends. Also, kids were viewed differently when Xers where children (i.e. The Omen, The Exorcist, The Bad News Bears) then when the Millennials were kids (i.e. The Olsen Twins - the cute little ones, not the skanky adult ones). Adults just liked kids more when Millennials were little then when Xers were. I think that in early adulthood, that really impacted how 20-something Xers viewed their parents and other older adults (negatively) and how current 20-somethings do (positively).
One other thing is that Xers, in general, tend to be a little edgier than Millennials in the way they communicate and in their humor. I think Millennials are used to people older than them (particularly the Boomers) being really nice and encouraging. But the Xer facade is just a facade. It's what we think is cool. Toughness. (Kind of like the Millennials think low-rise jeans are cool. Or how the Boomers think The Beatles are cool.) However, Generation X is so devoted to its friends, if Millennials make friends with the Xers, they will find valuable mentors and advocates (really).