While beginning knitters may have a hard time believing this, it's true. Knitting can be the type of mindless, repetitive activity, like walking or swimming, that lends itself to a meditative state. Scientific studies have shown that knitting can cause one's pulse to slow and breathing to become deeper, inducing a feeling of relaxation.
This type of relaxing activity is especially helpful for people who are facing long. And potentially stressful travels. Think air travel for claustrophobic people or the Hamptons Jitney for anyone. Knitting is portable, requires very few tools, is easily contained in a small space and offers the further benefit of allowing the knitter to watch something beautiful come off his needles.
Children as young as six years old learn knitting; it's often taught in elementary school as a way to teaching patience, manual dexterity and even coping with hyperactivity. By the same token, millenials are finding knitting to be an appealing alternative to staring at a phone during occasional downtime.