Do you lose skiing skill over time?

I have been skiing since I was around 2 years old. My father is the one who taught me even when I was too young to be in the ski schools. I have gone skiing every year since. However it has been about 3 years since I've skied. Last time I skied, it has been about 2 years since skiing. When I got back on skis around 3 years ago, I was wobbly for about an hour, then I was able to ride down double black diamonds again. Today, I am nervous that when I get back on my skis, I will have lost all that skill.

You might be a little rusty for an hour but it soon comes back...

Sadly, what you're more likely to lose over time... unless you work at it... is fitness. :(

Fitness aside I think is very easy to get a bit sloppy with technique over time (e.g. leaning into slope). Once you are a reasonable skier under most conditions it doesn't even show up so easily done.

Always have a few mornings with an instructor and always benefit from them.

Your fitness is likely to be the biggest variable. Also, flexibility is important and gets worse when you approach middle age. Especially if you sit behind a desk all day.