All free-born citizens were allowed to participate in the Olympic Games. Slaves and barbarians, i.e. persons of non-Greek origin, could not participate in the Olympic Games.
The participant must be honest, not cheat while playing. People who had committed a crime or were convicted of sacrilege were not allowed to participate in the games.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.