Do you dispose your mattress/foam after a certain period of time?

Hi I do not have a specific years in mind that if the mattress is say 6 year old then I will dispose it but I see the condition of the mattress. If the condition is good I do not change it but if the condition is bad then I would change it in 2 years too. But since the mattress that I have got says 5 year warranty and even after 7 years it us as good as new, I am not changing it, at least for now.