That's not good life advice. Being predictable would be pretty damn boring. Predictable people wake up, eat their bacon and eggs, shuffle off to the daily grind, put in their eight hours, go home, eat their steak and potatoes, go to bed. Rinse. Repeat.
They also survive their daily commute.
See, while being predictable is bad life advice, it's very good commuting advice. I do my best to ride predictably because that's what gets me home in one piece. I don't (er, try not to) hop and off the sidewalk, because drivers don't expect to deal with traffic coming off the sidewalk. I ride in the middle of the lane because the gutter has all the bumps and lumps and cracks that knock a cyclist about and cause us to dodge all around in ways drivers don't see coming.
To me, it's just another step to defensive driving. The best advice I got when I got my license was from my dad—drive like everyone else is an idiot. I bike like I expect every motorist to do something illegal and stupid that will kill me, and I ride predictably to make that harder for them to do. I follow basic traffic laws. When I arrive at a red light, I pull in behind the last car, just like another vehicle. I signal obsessively—and not always the legal signals, sometimes I just fuckin point so there is no way they can misinterpret what I'm about to do.
But this doesn't just apply to bikes. This applies to everyone moving about in our crowded world. Granted, this is Texas. If you want to ride unpredictably, there are tons of fields and farm roads where it is perfectly safe to do so. But if you're going to be on the roads and paths where there are other moving people about, you need to be predictable.
So you there, guy, running on the left side of the Katy Trail? You are not being predictable. You are in the wrong space and when I spot you I worry that at any moment you are going to dash across my path to get to the correct side of the trail. And you, dumbshit punk kids who jumped out at me from behind a fence, you were not being predictable. That's why I nailed you square in the shoulder and knocked you to the ground.
You were, however, predictable enough to scamper down the side of the trail where I couldn't chase you and fully chew you out, so, kudos.