It is easy to fool oneself into thinking one knows how something works, when in reality one only has a surface level understanding without really knowing about the internals. The serialization process exposes all the dangling pointers.

Your average person "knows" how a toilet works; water is pumped in to fill the cistern, released into the bowl when you pull the plunger, and flushes out the drain. Ask them to explain in detail how that happens, and most realize that they don't actually know how the cistern doesn't just keep filling until it overflows, or how it's not constantly leaking water into the bowl, or how the bowl can be flushed while neither overflowing nor draining completely.