In any household, junk accumulates to fill the space available for its storage.

Related:

• Possessions increase to fill the space available for
  their storage. --...
• Ryan's Application of Parkinson's Law:
  Possessions increase to fill the space available for...
• Possessions increase to fill the space available for their storage.
  Ryan's Application of Parkinson's...
• Biochemistry expands so as to fill the space and time available for its completion and publication.
  R. T....
• The amount of junk carried is in direct proportion to the amount of space available.
  Tony...
• Any given program will expand to fill available
  memory...
• The components you have will expand to fill the available space.
  Parkinson's (Modified)...
• The printed word expands to fill the space available to it.
  Parkinson's New...
• Work expands to fill the time available for its completion.
  Parkinson's First...