if we had ham we could have ham and eggs, if we had eggs

saying1

1. •
   Draws attention to the futility of a plan or strategy in the absence of the resources necessary for it to work.

   • The situation reminds me of the statement that "if we had ham, we could have ham and eggs — if we had eggs" — but in a world in which there are no hens. In theory, truly secure systems are impossible. — 1997