With our first two children, Tux Man was going to school full time and working (once our first child was born, I stopped working away from home until both our older kids were in school). This means that I have done this on my own before. I had expected to do the bulk of this work anyway, because I don't have to be at work the next morning and I'm really good at napping during the day.
So, I have been tired. And, as I think all babies do, our Littlest One sometimes fusses and we don't know why. This morning was one of those times, and I tried everything I knew to do and it didn't seem to help. I talked him through everything I did, and asked his opinions on what he needed, but to no avail. Finally, I told him I was going to wrap him in a blanket and see if he could fall asleep, because I suspected he might be really tired and need to sleep.
I tried it, and it didn't work... at first. Then I spoke softly in his ear and asked him to stop crying for two or three minutes, to see if maybe he really was tired and needed to sleep. I promised him that I would stay by him, so that I would be here when he woke up and he wouldn't have to cry until I came to him at that time.
And he settled down. And he fell asleep. And I fell asleep. And I nursed him in my mostly-asleep state, which meant that I actually got a 2 hour nap myself, and it's been another hour and a half and he is still asleep. So, I am staying here, watching him sleep.
I know there are plenty of times that talking to a baby doesn't work. But in general, I think we give them far too little credit for the intelligence they bring into this life with them.