It is normal for all of us to experience different emotions during the day, sometimes it happens to have a bad mood this reflects on our activities during the day, including work.
A positive epositive certainly has its benefits, but only if it is real, we often try not to reveal our positive emotions but this does not have the same benefits as a “real” positivity.
There is a difference between surface acting and deep acting, that is when one tries to express an emotion different from what one feels, and when one tries to internally change one’s emotion to reach a positive one.
There may be various reasons why you do not want to, or cannot have a positive feeling, in any case, when a change is internal, it is more easily understood by collaborators with better results.
Needless to say, a good mood has a constructive impact on the work environment.
If you are interested in the topic we recommend this article from HBR.