Boring books are sunk costs
If you find yourself not stimulated by what you’re reading (or watching), find something that moves you instead.
Putting in the effort to force yourself to consume content that no longer interests you only wastes the invaluable time you have. Time you could be spending absorbing something more engaging and potentially life-changing instead.
Walking out of the theater (and it’s literary equivalent) doesn’t mean you’re impulsive, finicky or pretentious.
It simply means you have better taste than the folks still glued to their seats.