why blog?

i know (or at least somewhat understand) why people like to blog. but why do we like it and push for others to blog as well?

1. is it because we feel unsure of our own reasons to blog, and find justification in the fact that others like to blog as well?
2. or to look all popular with a nice long blogroll? :)
3. to ensure that our blogs will be read if we read their blog? (tacit understanding between acquainted bloggers)
4. is it independent of our blog-writing? would we just like to get to know these other bloggers better by means of their blog?
5. to keep in touch with lives of friends without having to call them or see them? reading the blog can sometimes be enough....
6. or is it just to find more ways of wasting time? :)

others? please add to the list.

i find that 4 & 5 are most undesirably common, in my personal list at least. need to do away with this laziness right away. sometimes 2 & 6 also hold :). 6 often holds, in fact, for my own blogging ... getting back to work now (sigh).