> This is dream which happens only when you are asleep. In real life an older person is less energetic, less enthusiastic, can't do weekends, has health issues, has responsibilities, has family commitments etc etc.

This is complete nonsense. The best and most productive engineers I know are in middle age or beyond. In addition to raw technical ability--which does not decline in my experience--they have a level-headedness about making decisions that is rare to find in younger people. It's a critical success factor, especially for complex projects.