Yes, you can retire before your 40th birthday
Found on BBC on Saturday, 20 September 2014
Dropping out of the workforce years before everyone else, means you have to be completely debt free, with savings equal to about 25 times the income you wish to achieve in retirement, taking any government pensions or payments into account.
It depends on how dedicated you are to your cause, and how quickly you can pay off any outstanding debts (including paying off your mortgage) and accrue the required savings.
Now let's suggest that to the majority of people who barely earn enough with their jobs to get through their normal daily lives.