Moshe Mayor from Brooklyn, New York wrote:

Dear Rabbi,

The Gemara (Berachot 55b) states: Rabbi Zeirah said "Whoever sleeps seven days without having a dream, is called a bad person." Do you have any suggestions what did Maharsha say on this?

Dear Moshe Mayor,

As you may have noticed, Maharsha doesn't expound on this statement. He cross-references the two places in Tractate Berachot where this statement appears.

Rashi explains the basic idea as follows: Dreams are sometimes Divine messages. Seven days without such a vision indicates that the person is unworthy of Heavenly communication.

The Vilna Gaon has a different explanation: Life is like a dream, ephemeral and fleeting. If a person senses this, he will focus on the eternal purpose of life - studying Torah and doing mitzvot. Someone who goes seven days without sensing that this world is like a temporary dream has lost sight of the real purpose of life.

Why seven? Because for six days a person is busy pursuing a livelihood. He can therefore be forgiven for losing sight of life's temporary nature. But if he goes seven days - including Shabbat - without focusing on spiritual pursuits, he has abandoned life's real purpose.

Sources:

• Berachot 14a Berachot 55b
• Thanks to Rabbi Mordecai Kornfeld