I started my first journal when I went with my friend to Europe after graduating high school. I don't recall how I wound up buying a journal. It might have been at the airport. I would keep notes about what we did that day. We ran our camera through the x-ray machine before developing the film, so no photos. All we have is the journal.
Then, I started journaling when I went to university. I haven't stopped since. Although, back around 2007, or so, I discovered bullet journaling on Flickr. I think I started buying Moleskines around that time. Bullet journaling has been extremely handy for keeping it together. What ends up happening is that I get lost if I drop the bullet journal. I need that mental clarity that comes from thinking on paper.
I've tried doing this on Evernote and other tools. It works, somewhat. But, the problem with electronic versions is . . . squirrel!
Like you, I don't do the fancy stuff. At most, I will use different-colored pens or highlighters. But, that doesn't last very long. Mostly, I just need one pen.
RE: The Bullet Journal Experiment