When my closet/garage/desk is so full I can't stuff another item in it?
When I practically can't move because I'm so bloated?
It is never enough when it comes to money--I simply can never have enough, and what is "enough" anyway?
An interesting experiment I discovered has to do with tolerating the yearning for more without satisfying that yearning. Wanting and not "giving in" to the wanting by buying or eating the thing wanted. It forces a moment to moment struggle to the surface. It is a struggle with the feeling of desire that can be captured in the words, "I must have...". If surrender to desire is forestalled, what remains? Emptiness?Void? Frustration? Maybe a feeling of okay-ness with watching the desire ebb and flow. With a child the emotions may be persecutory: "You don't love me" or "I never get to have what I want" or "You never get me anything". Children know how to sock it to their parents. How should we best respond to our own wish for more and our childrens'?
"But I need it." Ah, there's the rub: need not differentiated from greed. When is it need and when is it excess? When does emotional hunger overtake reason and the ability to tolerate and not fulfill desire fly out the window? When to indulge and when to hold the line, because some indulgence can be a good thing. We're not talking about deprivation here, but rather seeking to understand and deal with a desire that nags until fulfilled---to the detriment of a reasonable and moderate way of life. We're talking about obesity, hoarding, bingeing, compulsive drinking, shopping, spending and the like.
So...the experiment. Observing, tolerating the feeling that appears when desire is resisted. Be with that feeling. Choose not to act on it or satisfy it through behavior. Discover what it's like to experience the wanting. What comes to mind? Is it familiar, does it evoke memories of the past? Are there body sensations that arise?
Most likely many feelings, thoughts and sensations will arise. If they can be accepted they may have something to teach and new information about what is essential and what is not will become available. This information can be a stepping stone to greater knowledge and control of unwanted behaviors.