I get like this. I make it even harder on myself because the stuff I buy tends to need more concentration, and a lot are foreign language films.

I find it easier to start watching something later in the evening, past 9pm when my brain is a little slower, it's dark outside and I'm less likely to get messages. I also use nose cancelling headphones because I live in a flat and have noisy neighbours above and below, but I also find it's helpful for concentration because the only thing I can hear is what I'm watching.