Know who’d pick up if you called at 2 a.m. Then make sure they know you’d pick up for them too.

The two in the morning list is short for everybody and worth knowing in advance. Finding out who would actually answer is not something you want to be researching while in trouble, and the people on it are often not your closest friends. The other half gets forgotten: being on somebody else’s list requires that they know it.

Name three people, honestly, and then tell each one plainly that they can call you at any hour. Keep your phone where it will wake you. If you cannot name three, that is useful information rather than a verdict, and it can change over a year.