I am knowledgeable in a field or two. But the most important knowledge was to understand that there will be tons who know better in any given field.
This leads to humility.
Being the smartest person in the room leads to hubris and stagnation. That then leads to getting humiliated for trying to apply the same smug attitude towards fields one is no expert in.
If you're the smartest person in the room, you're in the wrong room.