be miles away
US /biː maɪlz əˈweɪ/
UK /biː maɪlz əˈweɪ/

1.
estar en las nubes, estar distraído
to be thinking about something else and not paying attention to what is happening around you
:
•
I tried talking to him, but he was miles away.
Intenté hablar con él, pero estaba en las nubes.
•
She must have been miles away, because she didn't hear a word I said.
Ella debe haber estado en las nubes, porque no escuchó una palabra de lo que dije.