It seams like I haven't totally unlearned to cook.
When I was more into cooking it always contained lots of meat, but since I am basically stopped eating meat a year back and now vegan for two months, I had to do some things different.
Today I prepared a curry with sweet potatos and coconut milk, without any meat and at least my girlfriend pretended to like it, so it cannot be that bad ;) Also we are close to the end of one month without added sugar.
And to be honest, it wasn't that hard. Plus, I learned something about our world; there is sugar everywhere!
Products where you would never think about sugar, read the ingredients: SUGAR. It's a replacement, a filler, a sweetener. To sweeten stuff you can take fruits, you don't need to fill stuff, if you get whole foods, you don't need to replace taste, if you cook on your own. (By cooking on your own I don't mean deep fried stuff or instant meals.)
Get fresh food, look for the ingredients, and don't trust diet products.