Your doctor will ask about whether you've been feeling down or blue, whether you've lost interest in things you usually enjoy, whether you feel guilty or especially down on yourself, whether your sleep and appetite are disturbed, whether you feel exhausted most of the time, whether you are having trouble concentrating and whether things have gotten bad enough that you've thought some about ending your life.
And they will not be able to receive surprise presents, like special cookies or favorite movies, which are often brought to the space station on supply shuttles when someone starts feeling homesick or maybe a little blue.
"It's a very reassuring feeling to turn on the stove, see that blue flame and know you had a part in bringing a stable energy source to your community, " Glenn says.
Something about clicking on that blue-and-white thumbs-up icon somehow engenders just as strong a feeling of engagement among Millennials as owning more than one item from a brand.
Mr Hague has long seen this as the "clear blue water" between him and Tony Blair and there is some evidence that he is more in tune with public feeling than is the prime minister.