ELI5: Why do we age?

Imagine your body is like a really cool toy car.

• Building Blocks: The car is made of tiny LEGO bricks (your cells).

• Copying the Instructions: Every time a LEGO brick gets damaged, we need to make a copy. Your body has a copy machine (DNA) that tells it how to make new LEGO bricks.

• The Copy Machine Gets Tired: Over time, the copy machine gets a little bit rusty. It starts making slightly wrong copies of the LEGO bricks. These slightly wrong bricks make the car a little wobbly. That's like your body not working as perfectly as it used to.

• Accidents Happen: Imagine you drove your toy car through mud and bumped into things. These are like daily wear and tear (like the sun, pollution, or just using your body). This damage also makes your LEGO bricks break or become less functional.

• Cleaning Crew Slows Down: Your body has a cleaning crew to fix the broken bricks and remove the mud. But, as you get older, the cleaning crew gets slower and can't keep up with all the damage.

• Copying Errors: The instructions for your body's LEGO bricks get copied slightly wrong over time.
• Everyday Damage: Daily wear and tear damage the building blocks.
• Slower Repairs: The cleaning crew that repairs the damage slows down.