Translation of "L'imagine" in English

Mais lorsque je l'imagine,

But when I pictured him -

On l'imagine vraiment sympa.

We imagine it to be really nice.

Mais on pense moins au passé qu'on ne l'imagine,

But we think about the past less than we might think,

C'est en fait plus court et plus lisible qu'on ne l'imagine !

It's actually shorter and more readable than you might think.