passing the entrance gate to his property was a constant remind of what for frome? what changes?

From the text:

They turned in at the gate and passed under the shaded knoll where, enclosed in a low fence, the Frome grave-stones slanted at crazy angles through the snow. Ethan looked at them curiously. For years that quiet company had mocked his restlessness, his desire for change and freedom. "We never got away—how should you?" seemed to be written on every headstone; and whenever he went in or out of his gate he thought with a shiver: "I shall just go on living here till I join them." But now all desire for change had vanished, and the sight of the little enclosure gave him a warm sense of continuance and stability.