Whatever you put a lot of focus into in your waking life makes its way into your dreams. If you're always thinking about dreams and journalling, you're going to end up dreaming about it. It really pisses me off when I start dreaming about work, that's the worst.

You're probably right about having 10 different dreams in a night. Most people do. But every time you wake up after one and go back to sleep (to dream some more), the last dream is basically wiped from your memory. If possible, just scribble down some quick details of your dream in a notepad beside your bed to remind you in the morning. That way you don't lose much and get maximum recall. Even a couple of bullet points with key words is enough. It'll jog your memory in the morning and you'll be able to fill in the blanks of what you left out.