I have no accurate knowledge ...

I have no accurate knowledge of my age, never having seen any authentic record containing it.
I have no accurate knowledge of my age, never having seen any authentic record containing it.

More phrases

Courage - a perfect sensibility of the measure of danger, and a mental willingness to endure it.
 William Tecumseh Sherman
The same mentality that leads to environmental despoliation, environmental destruction, also leads to damage to people.
 Naomi Oreskes
You can't break poor people mentality. Once you grow up poor, you don't take anything for granted. It can have the negative side also because you can never truly be relaxed.
 Will Smith
The man with the average mentality, but with control, with a definite goal, and a clear conception of how it can be gained, and above all, with the power of application and labor, wins in the end.
 William Howard Taft
I think society had to grow up to the mentality of Peter Norman.
 John Carlos

Quotes from the same author

If there is no struggle, there is no progress.
I prefer to be true to myself, even at the hazard of incurring the ridicule of others, rather than to be false, and to incur my own abhorrence.
No man can put a chain about the ankle of his fellow man without at last finding the other end fastened about his own neck.
What to the Slave is the 4th of July.
A great man, tender of heart, strong of nerve, boundless patience and broadest sympathy, with no motive apart from his country.