The vertical red line

Have you ever had an experience where you suddenly notice something that has always been there but never caught your attention? I discovered this thin red line taped on a telephone post on my way to the nearby park. Someone might have placed it there recently, but I suspect I didn’t see it until now. As I walk down this street, my proverbial radar catches images of houses and people passing by. Or I am preoccupied with random thoughts, and my radar is probably not even turned on. There is a clear explanation as to why this red line caught my attention. A few days ago, I had been painting multiple red lines in the studio. That is why this thin line entered my world of consciousness and expanded it, ever so slightly. I wonder what other things am I not seeing?