"We might never see this again in our lifetimes," said Ryan Severino, chief economist at JLL, in his keynote speech at the GlobeSt.com Net Lease conference in Los Angeles. Severino was not only referring to the pandemic—the definition of a black swan event—but also to the pace of growth out of the downturn. With GDP growing roughly 5.5% this year, he called the rate of growth both "super normal" and "ahead of potential."

This year, the US will reach its highest growth rate since 2000, when GDP increased 4.1%. In fact, very rarely in the US history has growth exceeded 5%. In 1984, the economy grew at 7.2%, and in 1954, GDP increased 8%. Severino said that the 5.5% growth rate will put 2021 on the map as a historically notable year for growth.

The rebound in demand following the pandemic was the chief reason that the economy has rebounded back so rapidly, but Severino said that there isn't a single major force driving demand but rather a confluence of events.