I thought this was a pretty cool experiment, my own count was off by only two, give it a try yourself and see if you do any better:
".... The phenomenon of inattentional blindness seems to show you can see without the information crossing into your consciousness. Anyone can experience inattentional blindness. The phenomenon has been known about for a long time, but we can most easily get a handle on it by looking at a well-known experiment reported in 1999.
In this experiment, participants are shown a video of people playing basketball, and told to count the number of passes between the players wearing a white shirt. If you’ve never done this before, I urge to you stop reading now and watch the video.
Read the whole article https://theconversation.com/human-vision-what-we-actually-see-and-dont-see-tells-us-a-lot-about-consciousness-276310