Quality of life differs from individual to individual. It may be taken as family to family to absorb slight variations in individual’s routines. Every person has a say, though there is limited freedom. There are bondages, checks and balances and responses to them in a different way create a visible quality and activity change.
I usually attribute that to the limited (or partial) free will afforded to us by the Creator. That is how He would gauge our performances and possibly clamp approvals or otherwise to every individual performance. That brings in the concept of hell and heaven (limited to those only who believe). Rest: Allah knows best.
It could possibly be mental because it has to do what you believe in but it could also be social because you need your parents and peers/ culture to define who you are and what you choose to be
