What do you think is the difference between you and your wife? Men "tend" (observational) to sleep faster than women and I wonder if it is related to what I am writing about here. Women tend to spend their time on practical tasks that are more mundane for the mind, while men spend their time on more complicated, impractical thoughts that make the brain work harder. Massive generalisation without proof, but it seems this way.
but at the same time, it has taken away the wonder of seeing and feeling through your imagination.
You don't know the half of it. One of the issues I now face is I have almost zero motivation to do anything at all, so everything becomes forced by obligation. I know I should or have to do it, so I do. I think it is because without the spontaneous imagination, the "future" doesn't make impact on me.
Does your wife write each day? Keep a journal about daily experiences? I reckon it is worth a try and even if it doesn't help the sleeping situation, it enriches the life in so many other ways.