Understanding and updating beliefs on deeply engrained topics can take enormous efforts, but sometimes it can be so hard that the listener cannot even in principle accept the new reality. The listener is simply not ready, he lacks a vast background of reasoning leading to the new understanding.
What fact that you know is true but most people aren't ready to accept it?
By "you know is true" I really mean "you are very confident to be true".
Feel free to use a dummy account.
Defined benefit pension schemes like Social Security are grotesquely racist and sexist, because of life expectancy differences between demographic groups.
African American males have a life expectancy of about 73 years, while Asian American females can expect to live 89 years. The percentage difference between those numbers may not seem that large, but it means that the latter group gets 24 years of pension payouts (assuming a retirement age of 65), while the former gets only 8, a 3x difference. So if you look at a black man and an Asian woman who have the exact same career trajectory, SS pay-ins, and retirement date, the latter will receive a 3x greater benefit than the former.
Another way of seeing this fact is to imagine what would happen if SSA kept separate accounting buckets for each group. Since the life expectancy for black men is much lower, they will receive a significant benefit (either lower payments or higher payouts) from the creation of this barrier.
Defined-benefit schemes add insult to injury. The injury is that some groups have shorter lives. The insult is that the government forces them to subsidize the retirement of longer-lived groups.
In general, anytime you see a hardcoded age-of-retirement number in the tax system or entitlement system, the underlying ethics is questionable. Medicare kicks in at 65, which means that some groups get a much greater duration of government-supported healthcare.
unemployment welfare probably evens it out
fairness (and by extension discrimination) is entirely subjective. some think fairness is everyone with the same wage regardless of their productive output. some think fairness is zero taxes and charity