Many of us will have struggled to remember

[Maybo]

Many of us will have struggled to remember someone’s name when we meet them in an unexpected environment (a workmate at the gym, maybe), and we are more likely to remember them again once we’ve seen them multiple times in different places.

Source: Homework: is it worth the hassle? by Helen Silvester

What's the difference if I say "Many of us struggle to remember someone’s name..."?

 

[emsr2d2]

The original is referring to people's past experience of struggling to remember. Your version talks about a habitual action. They have different meanings.

 

[Maybo]

The original is referring to people's past experience of struggling to remember. Your version talks about a habitual action. They have different meanings.

Why didn’t the writers use the past tense to talk about people’s past experience of struggling to remember?

 

[emsr2d2]

Using "will have struggled" suggests a high level of certainty on the part of the writer.

 

[jutfrank]

Using "will have struggled" suggests a high level of certainty on the part of the writer.

Yes. I'd explain this as the writer's way of making a prediction about what is the case (the case being that many of us have struggled). It's a prediction with a high level of certainty.