Most people think compound interest is simple.

It is not.
$100 at 10% per year for 10 years.
Most people guess $200.
10 years x 10% = 100% gain. Simple math.
Wrong.
You actually end up with $259.
Here is why.
Year 1: 10% of $100 = $10.
Year 7: 10% of $194 = $19.40.
Same percentage. Very different dollar amount.
That is compounding.
You earn interest on the interest.
Time to double at 10%: 7.2 years.
(72 divided by your interest rate = years to double. Memorize this.)
Now flip it to 25% with the options layer.
$100k at 10% for 30 years: $1.7M
$100k at 25% for 30 years: $80M+
Same starting amount. Same time.
The percentage difference is everything.
Start as early as possible.
Let compounding do the heavy lifting.