Everybody feels underpaid. You earn more money, then you spend more money, then you wish you had more money.
I recently doubled my salary, and I still feel underpaid. In reality, I earn above median wage for my age and experience, and live a comfortable life. But we can always do with more cash.
There is a difference between wanting more cash and feeling underpaid. The fact the stat says only a percentage of people feel underpaid kinda rules out your statement that "Everybody feels underpaid".
