Many people do work post their retirement to earn for their living due to increase in life expectancy. I believe Working from young age do help individulas to attain retirement early and has many advantages.
The primary advantage is it gives an individual financial freedom from a very young age.They can take decisions on their personal interests, support education, start saving, travelling and many other things on their own and has to be less dependent on others. Many first world countries allows the teen to do part-time based jobs at an early age (around 14 years).Students who start working early can start saving early and can take retirement at any early age as considered to those who are starting late. This allows them to have good salary packages and save more amount of funds by the time they retire.
This is not only beneficial for an individual but also for a nation where youth is contributing to the skilled workforce. Unavailability of youth workforce is a major concern for many countries across the globe. Countries like India and China are considered to be blessed for more number of youth contributing to their economy.Many countries also welcome young talent to immigrate there and help boost their economy. The major reason is training a young talent is much easier for a company and it will be easy for them to extract more productivity the more they work for a company.
To conclude, Based on the few adavantages listed above, according to me starting employemnt at an early age will definitely help an individual to retire early.