He said in his book he had a copy folded away.That is weird! How often do people think about their birth ceretificate...when they have one?....folded or not!
It's almost making an excuse before it's needed!
I can say that at 9 years old I started looking for mine. Because I was adopted and was never told the truth. But I knew. I then asked for my brothers and it had been sealed and a new one replaced with adoptive information. Later in life the only birth certificate left on the planet for my brother was handed over by a relative.
My kids have theirs handy because it became something you had to have for passports and college, etc. I ordered several after the first problem so we had them available.