About DD and Nicholas Flamel

[Missy]

No: HPFGUIDX 69169

In interviews, we've been told that DD is around 150 years old.  
Nicholas F is over 600 years old.  Yet, one of the things DD is 
famous for (according to the chocolate frogs cards) is his work on 
Alchemy with NF.  Now- how old was DD when they started this work?  
And how did NF live so long before DD came along to help him with 
this work?  I've wondered about this for quite a long time, and am 
wondering if anyone has an explanation.  Thanks.

Missy (who does realize this is old news, and not the fun new news, 
but still a confunding thought)