The key to mindfulness practice, as Pema Chödrön said, is to return to the immediacy of your experience. I consider the idea of "return" as more important than any prescriptions of always being one way. From returning, there's an implication of change. Coming back. You may not always be present, in the moment, being here now. You could get caught up in your stories, your sensations of pleasure or aversions to pain, your attachments, which seem to cause you to suffer. You could get distracted with social media or rush to work or yell at your child. All these things could happen.
They are like clouds. Some clouds are dark, foreboding. Lightening slivers through them, striking a tree. Thunder rumbles, rain patters to the earth, soaking into the soil. Clouds shift, changing, obscuring the sun. Instead of identifying with these clouds, simply watch them come and go. They will change. They aren't something to identify with. They're merely there in your total awareness. Light will eventually scatter through them. You might see only clouds for a while, but if you watch them without judging, they'll drift away. Then there will be only sky.