Answer:
Albert Einstein quote is explaining that there are some things, that are extremely important for human beings, but that are not easily quantifiable.
This relates to GDP in the sense that GDP is only a measure of the monetary value of all final goods and services produced within an economy in a given year. While GDP can shed some light on a country's economic health, very important things for social well-being are not included in the GDP calculation.
This makes GDP only a partial measure of social well-being, that should be analyzed carefully when making conclusions about the economy and health of a nation.
