I think it's the distractions. I'm in my late 20s and when I was in college and didn't have a smart phone, I could hold my focus on a math problem for hours on

I think it's the distractions. I'm in my late 20s and when I was in college and didn't have a smart phone, I could hold my focus on a math problem for hours on a time. Now like you, I need to take a break and look at something else every 10 minutes.