Are there any mousy celebrities?
Can you be famous and unassuming?
Googling "famous and mousy" yields no results.
The first person who comes up in a search of the two words without quotes is Kate Middleton, girlfriend of Prince William.
And that's only in an article entitled, "Paris Hilton: 'I'd Date Prince William if He Dumped Mousy Kate Middleton."
So, being mousy has an advantage: it can keep Paris Hilton at bay.
That's her Kryptonite.
(Don't take this analogy too far.
It breaks down almost immediately, as Paris is neither a man, nor super.
Though she does seem nearly invulnerable.)