babies can't talk... but they can cry, so everything is associated with crying.. I can't sleep, I'm tired, I'm not tired, I'm lonely, I'm bored; I want to be left alone, I'm hungry, I'm thirsty, I'm grumpy, I'm annoyed, I'm awake, I'm hot, I'm cold, etc...
... and I think most babies cry at some point just for the sake of crying... They suddenly realise they are the ones making that god awful noise
Tia's 8 now... and there are times when she cries and I have no idea why... and it takes me ages and ages to get to the bottom of the reason... and she can talk.
There are times when we just cry because we can and there is no reason. Children are little people really... so don't ever look on it as a failing that you don't understand your LO... I don't think we are supposed to tbh...