How do I learn to stop dumbing myself down to make people like me?

I'm not stupid at all. I have a lot of academic awards, am shortlisted for a prestigious school title, am only 16 but have high hopes for the future. But for some reason, I subconsciously dumb myself down sometimes to get people to like me. I'm not talking about the odd blonde moment, because I am prone to them at times and find them amusing, but actually pretending not to know something or being less opinionated to get someone to like me. People have told me that they like my paradox of being intelligent and simultaneously clueless and find it endearing. Frankly, I'm just annoying myself. How can I learn to stop dumbing myself down to make people like me?