Old people have wisdom but not energy; young people have energy but not wisdom; energy and wisdom must be in the same body to create a much better civilisation! To do this, we will either give energy to the old or we will give wisdom to the young and for now the latter seems a more plausible action!
Your first purpose is to find a purpose for yourself. And your second purpose must not immediately be trying to reach that purpose you found but to investigate thoroughly whether that purpose is really necessary for yourself or whether it is worth at all to struggle for it! Because millions are fighting for a purpose which will in no way make them happy at the end!