Can reading too many books actually ruin the future enjoyment of reading?

I'm in the middle of Double Booked for Death by Ali Brandon, and I am thoroughly enjoying it. Being one who loves books and works in a bookstore, the setting of the book is ideal for me, and the respect for books that the character (as well as the author) shows throughout the story so far is refreshing and appreciated.

So far, the murder has happened and the clues are being pieced together in order to figure out the true suspect in the crime. However, I'm finding myself skipping ahead mentally to piece together my own idea of who the murderer is, and I find myself wondering:

Have I read too many books that now most things I read are just formulaic enough to figure things out before I get to the end? Has the fun of reading been ruined for me by the very fact of being a voracious reader? True, I could be horribly (and pleasantly) wrong about who I think the murderer is. We have the obvious crew of those who were closest and most mistreated by the ego-maniacal victim, who are the "usual suspects". Then you have the second tier of suspects who just might have done something to do with it because there is some level of motive... and I have watched enough crime shows and movies and have read enough murder whodunits to know that the usual suspects normally aren't the murderers and the second, or even third tier suspects are the ones you should have been paying attention to.

I think that Scooby Doo cartoons have had a hand in this "skipping ahead" phenomenon: while Scooby and Shaggy were running around being chased by the swamp monster, Daphne, Fred, and Wilma were off somewhere else actually solving the crime and piecing together what happened, selfishly keeping that knowledge to themselves until Shaggy and Scooby are nearly killed while capturing the swamp monster. Only once the poorly constructed swamp monster mask is removed do the trio reveal the true reason why Mr. Fitzsimmons was dressing up as a swamp monster to chase visitors away from the swamp amusement park to find the hidden Spanish galleon sunk over two hundred years ago and claim the millions in Spanish gold for himself (if it hadn't been for those meddling kids).... a deduction that even 8-yr-olds watching were left scratching their heads trying to figure out how those three put 2 and 2 together and got the square root of 83. Totally out of left field. From a young age we were forced to think outside the box and look for those random connections, or lack-of-connections, since Mr. Fitzsimmons had a 10 second scene at the beginning of the cartoon and never came back again.

Then, also, there are those crime stories that are more formulaic than Scooby Doo that famous movie star found murdered at a fancy garden party + jilted lover who happens to be invited to the garden party by a mutual friend of famous movie star = it really was the jilted lover that did it, case closed. I'm not sure where Double Booked for Death lands, which makes it a fun read. I truly hope I am wrong in who I think whodunit, otherwise I may have to either lay off the whodunits or give up on the fiction genre all together and try my hand at nonfiction.

I'll conclude this mystery in my full review of the book, which should be soon.