That’s exactly how I thought about it.

If you imagine a hypothetical person with a 2 year lifespan. During the first year the perceive time 1:1. But during the 2nd year they perceive 9 years passing during 1 year.

At 50% of their lifespan they will have 90% of their total perceived experience of time remaining.

I see what you mean, thanks. I'm not sure I entirely agree that life goes by more slowly, but at least they'd perceive enjoyable things as taking nine times longer.