There is a difference between being lost in thought and meditating that opens one’s awareness. In meditation, as in other activities in which the flow state is so important, one must remain in contact with the environment, in fact the purpose of the activity is to enhance connections with the environment, both inner and outer.
To do this, to have this luxury of developing a practice that expands our awareness, it is necessary to embrace the external reminders of the real world, for those are ultimately the things that seed our practice.
For more on Buddhist perspectives on working with our own reactions to disturbances outside of us, have a look at the practice of lojong mind training, a practice of working with the messiness in the world by developing our own compassion. Especially useful in this respect is Pema Chodron’s book, Start Where You Are.