Those who are thankful for the good things that God has given them will take good care of those things, whether it be their mind, car, body, spouse, children, job, etc. Taking good care of the things which God has given us shows Him that those things mean something to us and we are thankful for them. Not that we ever should worship the things God gives us, but we should take good care of them.
All of these symptoms should not be found in our lives, but if they exist (and I doubt many of us are immune!), there is something we can do about it. Develop a thankful heart! So the next question is….