Can a half-empty person become a half-full person?

It is related to perception------- We cant measure somebody is half empty or half full. Theoretically, an half empty person is already half full. He need to become other way.....

When this is decided by person himself -

If he decides he is half empty - it may indicate he is ready to take additional or it may also indicate his pessimism depending on the scenario. If he is optimist he can become full person......not half full!!