So finally I made it, I have been crowned legendary ! My actual activity is 868. I am glad I did not had to wait very long to become one !
It spent 29 days, 11 hours and 52 minutes to become one and I made 3095 in the meantime. Those numbers might not be exactly right, as I saw it now, and theorically I am one since Tuesday, but still it gives you and the posterity an idea.
Now theymos really needs to add another rank so that I can reach it !
Congrats to you. It is very encouraging when you have some goal to achieve, but on the other hand it cant be infinite types of rank. There is always the top.