At 300$ a month for 25 years and a return of 4% (conservative for the stock market), he would have ended up with 156k$ thanks to compound interest. Also: who w

At 300$ a month for 25 years and a return of 4% (conservative for the stock market), he would have ended up with 156k$ thanks to compound interest. Also: who works for only 25 years? You'd have to graduate (very late) with 30 and retire (very early) with 55?