Why does the same thing feel more valuable when it is almost gone?
Two cookies left in the jar somehow taste better than ten - and nothing about the cookie changed.
The scarcity principle is our tendency to treat things as more valuable when they are rare or running out. Limited supply works like a quiet signal of worth, and the chance to lose the option pushes us to want it more so we can keep that option open. The pull gets even stronger when the shortage comes from other people grabbing the same thing, not just from less stock sitting on a shelf.
You scroll Shopee and pause on a 199k jacket that says "only 2 left, 38 people viewing." The exact same jacket with "500 in stock" would not make your thumb hover - the low number did the work.
Rare or running-out makes the identical item feel more worth having, even when nothing about the item itself has changed.
Once you can feel scarcity pulling on you, you can ask "would I still want this if there were 500 in stock?" before a countdown timer or a low-stock badge decides for you.
Almost empty jar, fuller value - the last two cookies always look the tastiest.
Learn the idea and practice English at the same time.