Everyone knows this moment: you finish eating, get up, and only later – walking out the door or already somewhere else – you remember you never benched. Now what? Is there a time limit on saying birkat hamazon or a bracha achrona after you finish eating? Do you have to go back and say it in the same place you ate, or can you say it wherever you are? And the same question from the other side: if you already took a bite and swallowed, and only then remembered you never made the bracha – can you still say it, or is it lost?