Makem and Clancy say that the old Dutchman is still in shell shock. WWII gave him more than he can handle, and Margeret remembers how he was before the war. The first lines about not keeping his dreams in to me means in his sleep he has nightmares about what has happened, and Margeret is the only one who knows his terror. After the war he was so messed up that he wouldn't be able to help her raise children but she stuck by his side everyday. Her love for him conquers all, and he remembers that he loves her, and that when he calls her name when he thinks he's alone it seems like it's what he did during the war.

My interpretation anyway...