Based on the scenario being described within the question it can be said that the most likely reason for this misconception would be that the spiral galaxies looked like clouds of gas and dust through telescopes because of their distance from Earth. During that time telescopes were still not as advanced and could only see so much, nowadays they are much more advanced and these galaxies are being analyzed and understood more clearly.
Usually you can change that if you go to bed at like maybe say 7:30pm or maybe even 8, sometimes if you do that then you won't be tired in the morning. Hope this helped, have a great day! :D