The Tranquility of Materialized Views

Yesterday evening I searched the Oracle 10g documentation for the string "materialized views", and was browsing through the 378 matching entries in "Error Messages". At about the point where I got to ORA-12055: materialized view definition contains cyclic dependencies with existing materialized views I was overcome with a great sense of tranquility and understanding of materialized views.

Shortly after that I realised that I was probably delusional from lack of sleep or something, so I snapped out of it and went to bed. Is it still only Tuesday today?