Discussion: Book Nervousness

Hello dear people who read my blog and welcome back to another bookish discussion! In case you haven't noticed yet, there's now a page (link below the header) where there's a link list to all the discussions I've done in the past. You know, if you want to browse.

Anyway, today I'd like to talk about this weird sort of nervousness or trepidation that is sometimes part of cracking open that next book. Or settling on the book. Taking the leap. Bracing yourself to fall into a new story, a new life, a new world.

I don't get this nervousness with every book. Sometimes I just feel like reading it, crack it open, am sucked in immediately and feel comfortable. Other times, I'm almost a bit afraid. What if I don't like it? What if I'm left trying to swim in the deep end because I'm thrown into a strange world where I don't know the rules yet? What if I don't like this book? If it's a review book, will not liking it make me feel guilty?

With series, I tend to get it more often. I read the first book and I immediately want need must have the sequel. A year later, it's out. Maybe I buy it immediately. Maybe not. Even if I buy it, it might end up on my shelf for a few weeks, never mind how much I had to have it right this instant. What if it's not as great as the first/last book? What if I've built up the first book in my head and it wasn't all that awesome? What if I don't remember what happened at the end because I've read a few dozen or even a hundred other books since? What if I don't remember the freaking characters' names and who's who? That's why I often re-read the second half of the previous book before going into the next one.

There are also times when I feel like my own contrary nature is keeping me from a book. Let me explain: sometimes I push away / put off a book or don't listen to a band even though I half-know that I will love it. It's like denial of a desire, or me wanting to punish myself for some reason by not giving myself something I'll enjoy. I might pass it a dozen times in the book store and want to buy it, be drawn to it... but for some reason I always end up getting a different one.
Two examples? I was so sure that I'd never read Mara Dyer or Shatter Me. They were two of my favorite books in 2013 when I finally caved in and read them, about 2 years later. Why am I doing this? Does anyone else have that problem? It's like I'm afraid of the profound effect a good book can have on me.
Despite all that though, NOT having a book I'm reading immediately after finishing the last one makes me even more nervous! The next day at the latest, I have to start a new one.

What about you? Do you ever get this book-nervousness thing? Any ideas why? Has it something to do with specific books? What do you do about/against it? Or am I just a bit cray-cray?

P.S.: I'm visiting a friend in Belgium at the moment (this post is pre-scheduled), so I probably won't get around to answering comments until Monday.