Cycling involves repetitive motion. That in itself, puts the rider in a certain mindset. To counter that, it takes experience like riding with a group.

In a group ride, you do certain things. You watch the entire line, hear who is coasting, the cadence of the guy in front of you, their hand position, drops or hood, the curve of the road ahead, the traffic lights, the speed of the cars to your left, etc.

Active participation like this, even though considered very minor detail, is actually good to do.

This goes for driving a car too. There's more to skills than just driving at a safe speed and following the rules of the road.

The single most important thing "not do do"??? ear buds.