maybe the sweet spot will be 40 yrs old but do you think someone who is 40 and returning back to Doha, will he stay there for a long time? He will know that sometime in the future when he is over 55 years old, he might kick out of Qatar airways, hence he needs to make sure by 55 years old he has enough money to retire or fine an airline that respects the seniority list. This is the fact.