Fine is an emotion available in The Sims 4. It is the default emotion and usually occurs when a Sim has no moodlets. A Sim instructed to "Care for self" while on a different lot to the current one will feel fine.
Supportive Traits Edit
No traits affect how often a Sim is feeling fine.
Careers and Jobs Edit
No jobs or careers will gain work performance if a Sim goes to work while fine.