You probably skipped Step 86. If so just go back into the Meeting Attendance object (Setup > Object Manager > Meeting Attendance> and click Custom Fields and Relationships, click New and add it according to the Step 86.

But if you’re sure you did create it already and it’s just not appearing here, then the visibility for that field probably got turned off, making it “Hidden.” (This can happen when you create a field if your WiFi is really slow/spotty or if you clicked Next, Next, Save really fast – you’re skipping over those pages so fast their coding doesn’t fully execute.)

So just go back to Setup > Object Manager > Meeting Attendance, scroll down to Fields & Relationships and click on Enthusiasm, (NOT on Edit). Then click Set Field-Level Security (upper center of the page). Then click the checkbox next to the column-header Visible. That will turn on the field’s visibility for all user types listed below, including yours (Admin). Then click Save and when you go back to Steps 128, Enthusiasm should all be showing up properly.