It's natural. For a few reasons, here's why:
#1- Maybe you subconsciously knew that riding the hype train day after day since E3 will drive you insane and risk potential burnout for when the game finally comes out.
#2- You're focused on another game series now, that's cool. Right now I'm back in Saints Row playing around with the new DLCs.
#3- Maybe you're busy with other things as well? This was mostly the case with me, I had other things to attend to that distracted me from Fallout 4.
#3.5- You're excited about something else. For me, I'm more excited that Halloween is next month. It'll give me a legit excuse to watch horror flicks/play horror games and scare myself [censored]less. xD
#4- We haven't heard much from Bethesda aside from E3, a few articles and screenshots, the SPECIAL videos and demos. In some way, they feel confident that they can trust us to trust them that this is going to be as good as they say it will be, so maybe you're just not that worried about it?