You wrote: "My problem is that somebody apparently forgot to tell the Egyptians they were flooded and wiped out 4,000 years ago."
Why do you believe the flood was 4,000 years ago?
2252 BC -- layevangelism.com
2304 BC -- Answers in Genesis (+/- 11 years).
2350 BC -- Morris, H. Biblical Creationism. Grand Rapids, MI: Baker Books, 1993.
Most biblical scholars put the flood date, according to the timeline of the Bible, from 2348 to 2304 B.C.. That makes it a bit over 4,000 years old. Egypt had a unified kingdom almost a thousand years before that.