Both their parents have doctorate degrees. I expect John and Jane to receive a great education then go on to successful careers. There’s no certainty of that happening.
“Expect” does not mean with certainty, rather more like, “in all liklihood,” or “probable.”
Despite both their parents having doctorate degrees, there remains the risk that either John or Jane may fall into the wrong crowd and not attend college. However, I would not expect that to occur.
