The speaker lists a handful of ordinary pleasures: a fine dinner, tidy papers, an easy moment with his wife, a walk in the garden. None of them is out of reach. What stands in the way is "that itch," a fear he can't shake, and the whole poem hangs on the opening "If." The good life is described as something that would be simple to have, if only the fear would die.
The itch is a telling image. It is small, nagging, and impossible to ignore, and it suggests a worry that never quite names itself. The poem never says what he is afraid of, so the feeling stays vague and easy to recognize.
The mood is quiet and a little wistful. The short lines move gently, almost like a wish being counted off. Even "lie carelessly" carries irony, since carelessness is exactly what the speaker can't manage. The poem leaves us with the sense that peace is close at hand but blocked by his own mind.