The hard part about having true empathy for someone is this simple fact that: things feel different when you factor in time.
That's why it's almost impossible to feel the empathy for someone because to do so you would have to feel the toll of the years. How the years effected their story. How the years reinforced things and how it changed things.
Having empathy one day, is not the same as having empathy for 20 years.
Can you ever reach the level of empathy? Probably not, but when seeking deeper empathy with people, we must start by adding in time and simulating.
How would the story change from day one to year 20? How would domain knowledge change? How would experience change?
These questions and ideas influence the empathy factor you have for your customer.