Being told not to, then told to

Contradictions... My family is so good at them. The best way to explain it is through examples...

When I was 6 or 7 I told my mom I wanted to be a chef, just like her and my big sister. She looked at me with disgust and told me I wasn't allowed to be one, because the family already had two, we didn't need a third. At school in grade 9 we told to start figuring out what we want to be. I can home and told my mother this and she told me I was suited for desk work because I wasn't a very smiley person... That was a couple of years ago... She told be last month that the man she works with thinks I'd make a good chef (I was working there for about 4 years as a dishwasher) and she asked me why I don't pursue that as a career? I looked at her like she was out of her mind and told her, that she had told me I wasn't allowed to be that. She then looked at me like I was crazy and said she had never said such a thing... What does that say about me? That I heard wrong? That I remembered incorrectly? That I am stupid for remembering something like that when clearly she doesn't...

Another example. My sister and I were watching tv and I commented on something, lets say it was about sharks. She will then discuss why what I said was wrong, I'll let her be and say I could be wrong, but I don't believe I am. We google it and what does it say? I'm right! -- About 2 weeks later we're watching and the same shark show is being broadcast. My sister then tells me a fact she learned on the internet about sharks.. the same fact I, 2 weeks ago, had told her. I say I knew that and that I had told her and she gets pissed and says that I'm lying... I have of course no way of proving I'm right and vice versa. Am I the only one in this family with a memory? Am I the only one that cares?