小时候一张床单咱就是超人
[xiăo shí hòu yī zhāng chuáng dān zán jiù shì chāo rén]
This is a recollection of childhood innocence and imagination. 'As a kid, with just a bed sheet, we became superheroes.' Here the user seems nostalgic for times when even something as simple as a sheet was transformed into a symbol of power or adventure in youthful make-believe.