Stupid joke statement and a sign of a person who has never thought critically in their life.
Thoughts?
Well really it depends on what happened before the comment. If one isn't taking life very seriously, ie, doing reckless things, whinging about typical stuff adults have to deal with or just being a little bitch then yeah, the statement is good and the person being told it should grow up and take life more seriously. On the other hand, I'd imagine most times it's used against somebody who is just enjoying life more than speaker thinks they should, in which case screw them, keep on enjoying life.