I'd expect that there are a number of factors that help improve your odds, and that being "smart" will be one of them. But so would being born into a wealthy family, or just bing born in a developed country, and be of good health, and any numbers of other factors.

As well as a huge amount of chance - e.g. my first company got funded because one of my co-founders ran into a guy in a bar that happened to be in the country for a week or two. Maybe we'd have found other funding if that didn't happen. Maybe not. We'll never know.