Can I Change My Rating, Or Should I Re-read?

Today, I have a question for you. Or a discussion? I guess that depends on how you look at it. I keep Excel files on my reading, because I like to feel organized. So last week, I was really happy to see that I had managed to review every single book I had read in 2016. Isn’t that great? I reviewed everything! The euphoria and pride was out of this world. But then I opened a different Excel tab called “books to review from 2015”. Yes, I had 28 books I read in 2015, I had never reviewed. I wanted to take on the challenge and start writing reviews on those too! Then I encountered a problem… 

I didn’t agree with my ratings anymore.

For example, the Falling Kingdoms series. I read book 1-3 last year, but never reviewed them. When I looked at my ratings, I gave them a 4.5, 3.5 and 4. Because at the time, while I didn’t love them, I did enjoy them. However, when I think of them now, I consider them more 3 to 3.5 star books. Here’s where my question comes in: can I just change my rating, or does that warrant a re-read first? Here are some of the arguments. 

I should re-read first because…

As it’s been a while since I read them, I am only basing this on memory. But what if I just forgot a lot of stuff I enjoyed? What if time distorted my view, and I really did enjoy them that much? I feel like I should re-read them because it may be unfair to rate a book simply based on distant memory. 

At the time, that seemed like the right rating for them. So without re-reading, how can I really say that I’m 100% sure I’d enjoy them less now, or rate them lower? I can’t be 100% sure of that. 

Basically, it feels like the only honest way to change a rating. How can I base it on a distant memory, or say that I believe I’d feel differently now? 

I shouldn’t re-read first because…

Let’s be real, I don’t have time to re-read each novel. I’m hesitant about quite a few of my previous ratings, but I simply can’t find the time to re-read them all.

Even if it’s distant memory and I can’t be 100% sure, if I can sum up reasons as to why I’d change my rating, shouldn’t that be enough? Let’s keep with the Falling Kingdoms example. Now, I think that it wasn’t really that captivating as I have no burning desire to continue the series. I found some of the characters boring, and others creepy -and not in an interesting way. Overall, I think it is massively overhyped -although it’s definitely not bad (don’t shoot me!). Shouldn’t all those reasons be enough to change my rating? I don’t feel like re-reading them all, just because I believe I wouldn’t enjoy them as much. 

So, what do you think? Should I re-read first? Should I just change it? Should I mention in the review I’ll write that I’ve changed my ratings? Make a comparison between just-finished-rating and a-year-later-rating? I’d love to hear your thoughts, and maybe you could even help me out of my dilemma.