Shaw is doing something rather clever here—he's not talking about penny-pinching or frugality at all, but about the disciplined allocation of attention and resources toward what genuinely matters. Most people assume economy means deprivation, when Shaw means it as the opposite: the wisdom to spend yourself wisely so nothing of value gets wasted on the trivial. Consider how a person might work a job they tolerate to fund hobbies they forget about, while neglecting the friend who calls monthly—that's poor economy of life, not poor accounting. True economy, by Shaw's measure, is recognizing that you have only one life to spend, and spending it well requires saying no to nearly everything to say yes to what counts.