道 is a head 首 walking 辶 — a person moving down a road, thinking as they go. It named the physical road, then the method, then the Way itself: how the universe moves.
知道 'to know' is literally 'to know the way'. 道理 is reason, 味道 is flavor, 街道 is the street. And then there is the 道 of the Daodejing: 道可道，非常道 — 'the Way that can be spoken is not the eternal Way'. One character spans asking directions and asking everything.
A head 首 walking 辶 the road — the WAY, in every sense.
Chinese martial and fine arts all end in 道 by way of Japan: judo 柔道, kendo 剑道, sado 茶道 — the 'soft way', the 'sword way', the 'tea way'. The Dao exports well.