It was the case of a lofty and aspiring soul craving with more eagerness than caution the beauty and splendour of great and glorious renown. But it was soon mellowed by reason and experience, and he retained from his learning that most difficult of lessons -- moderation.
Agr Chapter 4: His parents

He sought to make himself acquainted with the province and known to the army; he would learn from the skilful, and keep pace with the bravest, would attempt nothing for display, would avoid nothing from fear, and would be at once careful and vigilant.
Agr Chapter 5: In Britain

When his public and judicial duties required it, he was dignified, thoughtful, austere, and yet often merciful; when business was done with, he wore no longer the official character. He was altogether without harshness, pride, or the greed of gain. With a most rare felicity, his good nature did not weaken his authority, nor his strictness the attachment of his friends.
Agr Chapter 9: In Aquitania

Should posterity wish to know something of his appearance, it was graceful rather than commanding.
Agr Chapter 44: Obituary of Agricola