When “Stay Positive” Helps — and When It Harms
In the face of adversity, many are advised to “stay positive.”
However, this short, simple statement can mean two wildly different things — and, thus, have wildly different consequences for the person in question.

Meaning 1, or When It Helps: Resilience
Being able to overcome the challenges of life is a significant skill to have.
Resilience (according to American Psychological Association) is the ability to adapt successfully to challenging circumstances — and, thus, maintaining or improving your mental health. As resilience expert Lucy Hone claims in her TED Talk, this involves actively choosing not to become a victim of your circumstances. Instead, it involves focusing on the aspects of your life that are within your control (which you can still do something about to move forward), rather than the ones outside it.
Read my article (here) about building resilience.
In this sense, “staying positive” can mean keeping your focus on the bright side as you make your way toward it, without being held back by your more unpleasant emotions.

And doing so can prove to be quite helpful. As (likely) any textbook that covers resilience can tell you, meeting challenges with this kind of mindset can make you more impervious to the negative effects that such a situation might otherwise have on you. After all, as APA claims, a person’s outlook often determines how well one handles — and overcomes — a challenge.
However, this brings up an important point in the “stay positive” discourse:
Meaning 2, or When It Harms: Toxic Positivity
Resilience entails actually handling your emotions — not avoiding them.
Sadly, it is easy to confuse unpleasant feelings (sadness, anger, jealousy, disgust, etc.) as harmful in themselves, and seek to overpower them with pleasanter alternatives. Toxic positivity (according to Psychology Today) refers to this act of forcing yourself to remain positive by choosing not to process your so-called “negative” emotions. This can involve pretending your emotions away, denying their existence, or using similar unhealthy regulation strategies.
In that sense, “staying positive” can mean not giving your emotions the attention they need and not properly listening to your needs as a result.

And that can be a harmful habit. Because if you want to build resilience and master stressful situations, you have to acknowledge your emotions and handle them accordingly — constructively — along the way. Ironically, if you try to suppress your emotions in an attempt to remain positive, you’ll inadvertently become a victim of your emotions after all.
So yes, stay positive. Not because “positive” is what you have to feel.
But because “positive” is the impact you should make through what you do.