I sometimes go on 8 hour car rides and don't require entertainment. Maybe it's just my personality, but the key is to foster interests that can live in your head. It's possible to spend 8 hours thinking about musical temperament, or lapsteel tunings, or word etymology, or writing song lyrics. Boredom just means you are used to low-effort stimuli being readily available.
I got asked on a 2.5 hour flight recently why I wasn't reading or looking at my phone/laptop. I like just zoning out and thinking about things. It's almost meditative, and being on a plane without internet access gives me a good reason not to be staring a screen for a change.
