Retired people generally are a lot older and get income from things like Social Security. They also get medicare taking care of health insurance. Between those two you need a lot more money to retire before you turn 65 vs after.

Now I believe he is in Europe so different rules apply, but they have similar things there). I don't know the rules in his country (or even his country), some are more friendly than others, but still the money won't go as far when you retire before the system wants you to.