YABU
My experience of prolific facebook users (of which I am one) are that they either:
a) have masses going on, lots to share, lots to update people on etc.
b) have a very strong political/religious/social stance that they like to share about
c) have a lot of spare time on their hands
d) find real life interaction quite difficult due to logistics, personality, health or mental health
e) are serious procrastinators