Let's suppose, you noticed one day a new mole that has appeared on your skin. You start to get anxious that it may be cancerous, so you avoid getting it checked out and secretly hope it'll go away on it's own.
Does it sound like you have done it in the past?
Sometimes people are afraid of taking action because it may reveal a truth that they don't want to hear.
So, the old phrase "What you don't know can't hurt you" isn't true. If you ignore something for a long period of time, hoping it will go away, it will only get worse.
This kind of fear can lead to misinformation to an individual's memory and continues to influence their thinking, even if the person is aware that they are mistaken. The person is also likely to make use of misinformation, especially if it fits with their existing beliefs and makes a logical story. This then leads to spreading the inaccurate information to others.
Having misinformation or preconceived notions about health issues (e.g "Cancer does not run in my family, so I am probably fine" or "The mole will go away with time") can end up doing significant damage.
When it comes to personal health issues, ignoring the problem instead of facing the truth can certainly lead to a more severe issue and even death.
Think about it: What if the mole is a form of cancer that is completely treatable during the early stages but can grow malignant if it's ignored?
You could be proactive in getting the mole checked out and it would be an easy fix, or you could procrastinate because you want to assume that everything is okay. In this case, what you don't know certainly can hurt you, and your personal belief that it will go away on its own is detrimental.
If you are overweight or obese, assuming that it's fine to be like that as most of people in my circle are like that and it's absolutely normal. Aren't you inviting a bigger in future? Remember: Body will never hold extra weight if it's healthy from inside. You must know your current health parameters like fat %, muscle weight, BMI, BMR, Bone mass, Bone mass density, thyroid function, liver function, kidney function, vitamin and cholesterol levels, sugar levels, etc.