What it means
The Sun is the self in Jyotish: ego, vitality, the part of you that wants to be seen. Where it sits sets how loudly that part speaks.
Leo is the Sun's own sign. Aries is where it is exalted. In both, the Sun is read as strong and unembarrassed. Texts describe this placement as the front-row type: confident, direct, uncomfortable staying in the background.
The same strength has a cost. A strong Sun can mean stubbornness and a hard time taking advice. Tradition says so openly.
Roughly 1 chart in 6 passes. Look at your own life. Do you end up leading even when you did not ask to? Send this to the most visible person you know and see if it fits.