Alice has a car that can only drive at 65mph.
Bob has a car that can drive at 70mph.
Every time they both drive 70 miles to the city, Alice spends almost five extra minutes driving.
When Bob’s car breaks down, he borrows Alice’s car. Driving it, he constantly has his foot on the accelerator, to no avail. The visceral slowness is encumbering and distracting. He spends more than an hour overcome with frustration, plus that extra five minutes driving.
Bob finds it hard to believe that Alice puts up with this, and supposes she must be really struggling in life, or making errors of judgment, if she hasn’t got a new car already.
There are many ways that you can fail to appreciate how bad other people’s problems are. But I think you can also systematically fail to appreciate how bad they aren’t, for the person. What is salient in moving from your world to theirs is not necessarily salient in theirs, so when most of the cost is from the salience, you might be overestimating it.