The next time someone tells you that you have the attention span of a goldfish, you should rejoice at the compliment. A Microsoft survey in 2013 seems to suggest that the attention span of a goldfish is 9 seconds, while the average attention span of a human is 8 seconds. That has fallen dramatically from 2000 where the average attention span of a human was 12 seconds.
We may all blame the advent of social media and the rise of the smartphone. I would rather focus on exercises and practices with the goal of outperforming a goldfish.