It varies; but generally speaking, I think they're reasonably well informed...........the problem is, everyone has their own version or perspective of what is "Lebanese History"...
Meaning that, if you ask a Sunnite, a Maronite, Shiite and a Druz to explain to you Lebanon's' history..you'll get several different stories and versions.....
There isn't one unified sense of National Identity
In terms of culture, most "youngsters" (ages 18 and above) I know are pretty well informed and appreciative of their traditions and village roots... Ages 17 and below, they pretty much don't know squat beyond the currently prevailing American heritage and culture!?! Even the local French culture is dissipating to a certain degree