She's 76 years old. She asks me what the date is about 3 times a day. The day before yesterday she said something like ''Oh, so it's September already?''. Yesterday she asked me if it's May or April. She doesn't orientate in time at all. She forgot how to cook anything. Although, she could still cook 2 years ago. The only thing she still knows how to cook is pancakes. When she opens the fridge she can't see anything. She says that it's empty, but it's not. I have to take food out of the fridge and give her. She was much different 2 years ago. How is it possible to change like that in just 2 years?

I sometimes didn't notice because I saw her pretty much every day of my life until she died (plus she had conditions which were more, well, noteworthy). You become used to it and only notice the deterioration if you're away from it for a bit.
If your grandma hasn't been diagnosed with anything, it's worth getting this looked into. My other grandma lived to pretty much exactly the same age and she was as sharp as a tack.
People have been lead to believe it's normal to be forgetful in old age but it's not actually all that common that it can be expected to be the case most of the time.
Unlike the typical sweet-hearted, dainty grandmother, my own cantankerous grandmother, when i demand that she get off the couch and make me pancakes, Old Yeller gives me an icy stare, and tells me to "make them myself". Furthermore, she criticizes my pancakes if they dont come out fluffy. This really hurts my feelings, when she starts yelling at me:(
But i give her licorice and puzzles, and that keeps her busy until its nap time.
I have to admit it made me laugh though.
So again, answers like yours are not helpful at all. Neither for the IIN community, nor for people asking questions. I suggest that the next time you see a post that looks like a troll post to you, just ignore it.
As you say I shouldn't have replied, you could have just as easily ignored my post.
No reason to be butthurt because you didn't know what the fuck Alzheimer's was.
I'm not posting shit. I wanted to know if that was normal behaviour for an old person. That's what this site is for, right?