Frequently in Buddhism teachers and others will use the analogy of emptying the teacup. It is a good image when you consider that before you can receive more tea, fresh tea, hot tea, different tea you need to first empty your cup. If your cup remains full then there is no space for more. The same goes with our lives. If we cling tightly to what we have and do not seek to give it away then we have no space for more. If we are feeling good and have received merit from our practice of Buddhism what good does it do us to cling tightly?