Views really come from your audience and this can be reflected in them not enjoying your content, or if there are not interested in that type of video. Don't forget it would be very very rare to see a viewer / subscriber who watches every video someone creates without fail. Views can also fluctuate based on a number of different things and can really be dependant on the people watching your videos
I'm sorry to hear that
A trick I learned is before your intro make a little spoiler of something awesome that happened in that video but cut if off right before the intro! And make people like: I want to to see more, what's going to happen next? Make them curios but don't let them wait in the video.
If you mean your own views are decreased then i'm sorry to hear. It could be due to change of content or a temporary issue due to vacation period. Don't let it get you down though