Being mindful isn't intended to mean being vigilant at all times. Indeed, quite the opposite is true. The ultimate experience of being mindful occurs when we forget about everything, even the mindful self and doing. A paradox it is that to be mindful one must not try to be mindful, and to not be mindful, one must be mindful.
Can we cut it short? The answer is yes. We can skip the mindful thing. How? By just doing what we like to do when we feel like doing it in the way we feel the best. No thought, no mind. It's a vacation of the mind so to speak. You kick the mindful thing out of the equation from the start.
Total physical immersion with mental emptiness. Just doing.
For most of us, this is quite a challenge. As in a rock climbing we use a niche or a thing to place a foot or finger in to grasp, we need somewhere tangible to place our mind. Something to think about or focus on keeps us oriented. It anchors the mind to a specific moment in time preventing it from fleeting. It keeps our awareness contained within our body so that the body does not do things randomly.
Once the mind is contained, the body can fly.