Node's promise chain call

var bPromise = new Promise(function (resolve) {
    console.log('start');
    resolve(100);
});
bPromise.then(function (value) {
    return value * 2;
}).then(function (value) {
    return value * 2;
}).then(function (value) {
    console.log("2: " + value); // => 100 * 2 * 2
});

The output is as follows:

start
2： 400

The above code looks like, the function in the promise is executed only once (only one start output), even if there are multiple thens.
It does, and here's why:
every promise object that executes then is a new object! A new object is returned from the previous then.