Lying around

As I  was lying around, pondering the problems of the  world, I  realized that at my age I don't really care anymore.

..  If walking is good for your health, the postman would be  immortal.

.. A  whale swims all day, only eats fish, drinks water, but is  still fat.

.. A  rabbit runs and hops and only lives 15 years, while  a tortoise  doesn't run and does mostly nothing, yet it lives for 150  years.

And  you tell me to exercise?? I don't think so.