Will our coding skills fade with time?

First my personal view for my future as a dev, please comment and give me yours.

I'm a 34 year-old software engineer. Started as a technician at 16, then developer while stuyding at uni (22). Studied in the US, worked in the UK (5 years). I consider myself intelligent enough to give some value in a daily basis but not a great developer (I've always found brighter people)

I consider people thinking abilities do fade out with time like a football player's body. I'm worried that I will not be able to cope with coding in 10 years time (my mind with get tired and my spirit too) My plan is to slowly switch to a more management area (founding my own company or working for someone else), but I dont think it will be possible to keep being a good dev. For this im saving money, investing, and trying to take the best of this time since I know it wont last forever.

I wonder if my view of the future as a developer is being realistic or pesimistic.

What is your plan? Is there a due date for our minds?