Multi monitor setup?
No I can keep stuff in my memory.

Give it 10 years and see how you feel. 😅

I'm 50 and still can do massive coding of the more complex type on a single MacBook Air ...

Multiple monitors is not for memory, it's for efficiency. I can have a website on one monitor while coding on the other. I can watch the live updating page while making edits to my code.

I can't go back to a single monitor again, it's just too slow for me to toggle between stuff all the time.

@Xevion this is the reason for me as well