De Bruijn's theorem
... that Nicolas de Bruijn was inspired to prove De Bruijn's theorem on packing bricks into boxes by his seven-year-old son's inability to pack some bricks into a box without wasted space?
... that <a href="./Nicolaas_Govert_de_Bruijn" id="mwEkM" rel="mw:WikiLink" title="Nicolaas Govert de Bruijn">Nicolas de Bruijn</a> was inspired to prove <b id="mwEkQ"><a href="./De_Bruijn's_theorem" id="mwEkU" rel="mw:WikiLink" title="De Bruijn's theorem">De Bruijn's theorem</a></b> on packing <a href="./Brick" id="mwEkY" rel="mw:WikiLink" title="Brick">bricks</a> into boxes by his seven-year-old son's inability to pack some bricks into a box without wasted space?