The neurons in your brain don't function correctly until they've grow their nice cozy layer of fat called myelin. When you're born, some of your neurons are fully clothed, but most are not. The myelinization process doesn't reach full completion in the average human male until about the age of 49, plus or minus about a year.
Sometimes computer programs are written by programmers younger than 50. Those programs are usually trash, and it's easy to see why. Most of their brain cells are shivering to death stark naked, waiting for the magic fatty ritual. And it will be a long wait. Sometimes you see programmers trying to increase the quality of their code by increasing their fat composition by eating sugary sweets in abundance. In all fairness, this practice does yield some beneficial short term result (this according to some unpublished studies by Capers Jones), even though brain development is being retarded, not advanced, by this practice.
If you're under 50 and thinking of thinking, please accept some advice from someone who's been there, done that: Don't.