Ghosting could be a thing. 

OR MAYBE we just have no freaking way to tell who has yet to receive a response from us. 

Sure, we might be flighty little millennial monsters.

OR MAYBE we really want to respond to people we love and can't quite remember whether we did or not.

1. We can mark emails as unread.
2. We can mark Facebook messages as unread.
3. For the love of all that is sweet and juicy and holy, Apple Inc., let us mark our texts as unread.

It's simple: we can check messages and then click "mark as read," simply add text that says "mark as UNread" and the corresponding functionality, sirs and madames. 

No really, do it. Please and thank you,

Earth.

PS > Every second, four hundred thousand million text messages go unanswered due to lack of unread button access. This must stop.