As a former writing teacher, and one who included journal writing as part of my class, I just can't make myself sit and do it. I used to journal when my students were writing, but it seemed like I wrote about the same stuff over and over; which kids were doing what, just stuff about the day. Boring and mundane.
I have no desire to keep a record of my day to day stuff. I'd really like to sit down and write, as in fiction, but I can honestly say, that will never happen. I know I could do a decent short story, but I am not disciplined enough to sit and do it.
Blogging, meh. No one wants to hear what I do. To me, it's like Facebook. I hardly ever post there, because unless I tell you something personally, I don't need you to know about it.
And, I am glad I don't have a written record of my teenage years .