"To you first entering on life, to whom care is new, and agony unknown, how can you understand what I have felt, and still feel?"

   At the time of their meeting, both Frankenstein and Walton are in their mid-to-late-twenties.  This remark can be taken either as Frankenstein asserting that his nightmarish experiences have aged him beyond his years, or as further evidence of his boundless capacity for self-pitying egotism.