Interplanetary Travel

Please can someone advise me on how to retrieve Dr John from the planet he is on?
I don't mean this in a flippant way, I am very serious as he is driving me insane.

He doesn't just seem to daydream, he just seems unable to focus on things. Not just educational ones either. Today he sauntered into the kitchen wanting a drink, so got the carton of juice from the fridge and wandered off with it. When I called him back to pour it into a glass, he almost seemed unaware that he had it in his hands!

He has been saying every now and then that he is bored, but I just need to suggest something and he is okay again.

Any thoughts? Is this something that is characteristic of 5 year old boys? Do I have to grin and bear it (I'm trying very hard not to get cross, but it is annoying me somewhat!)?