This line from Wikipedia made me want to ask this question:
There is, however, no general procedure for determining whether an expression involving looping instructions will halt, even when humans are tasked with the inspection. The theoretical reason for this is the undecidability of the Halting Problem: there cannot exist some algorithm which determines whether any given program stops after finitely many computation steps.
Wondering what this is and what it means. Why is the Halting Problem undecidable. I don't understand, I feel like I could tell if a program terminates or not. Wondering what an example is of a program you can't tell will terminate or not.