It's not that Doumeki doesn't listen. He knows that some, though only sometimes, of the things that Watanuki says when he's ranting are important. And he knows that if Watanuki is ranting about it then it is something that is important to Watanuki (if not anyone else) and most things that are important to Watanuki are important to Doumeki (although it seems that the number one thing that is important to Doumeki – namely Watanuki's safety – never seems to cross the mind of the spastic teen at all.) He figures though, that if Watanuki is ranting about something either he has heard the complaint before or that he had realized a while ago what was happening and had taken action to fix it and Watanuki, being Watanuki, hadn't realized it until that moment – because he was Watanuki and Watanuki was a bit slow. No, Doumeki's problem isn't that he doesn't listen. His problem is that he already knows and hasn't told Watanuki, because Doumeki is Doumeki and Doumeki is hoping that Watanuki will realize for himself.

Watanuki doesn't have a problem with hearing, nor with listening. Of course its the people around him that have a problem with listening. The great Watanuki simply doesn't grace meaningless talk with the attention it seeks, that's it. Of course it doesn't have anything to do with the fact that he could arbitrarily disappear (as it seems from his side,) or that he could be forgotten at any given moment as easily as he forgot his parents. It also has nothing to do with the fact that the people around him are very important to him and he can't help but want to tell them how much he appreciates them, but can't because he doesn't know how. Its not as though Watanuki is so dense that he doesn't know. He just decided that he won't tell anyone quite yet. Because he knows that he's not fooling anybody.

Watanuki is not scared of being alone.

That would be just silly because Doumeki will always be there.