How do I inspire my brother intellectually?

ok this is an interesting subject because this has happened in my family. I have two sisters, ones 21(the smart one) and my 18 year old sister (the mild intellect) and me(well Im smart and sporty) when I was young I was too interested with football and I though I would go pro. It wasn't till my dad strait on told me It is very hard to go pro and I probably wouldn't make it. I was shocked but that year my sister was excepted into a few ivy league schools. That year I went into honors math and honors english. I already know what i want to do in my life(Architecture) and Im 13, that doesn't mean i give bad advice but im pretty young. To sum it up you want to either tell him of the accomplishments you've gained through academics or make him accomplish something. If worst comes to worst strait on tell him I was 8 and I got over it. hope it helps (=