Federal Reserve Governor Stephen Miran entered with big ideas about how the central bank should change— radically so, in some cases. As he prepares to step down in the coming days from what will have been the shortest tenure as a governor in 71 years, he appears convinced his ideas are right.

But in a CNBC interview, Miran, 42, made clear that the reality of working at the Fed has tempered his views about how fast those changes can be made. Change is slower than he envisioned.

The Fed is "really a committee," Miran said. "It's different than an agency where there's a very clear executive who just runs the show, and what he or she says goes, and if you don't like it, you're out."

That observation is important for two reasons: First, Miran could return as a governor, potentially before the end of President Donald Trump's term. Second, incoming Chair Kevin Warsh shares some of Miran's big ideas.

Warsh was confirmed as the next chair on Wednesday and will take the board seat Miran is vacating. The two won't overlap.