feel in one's bones that 十分确信
A: Do you believe Tom's promise?
B: I feel in my bones that he's lying.
A: Yeah. He always breaks his words.
feel one's age 觉得老了
A: How nice to see you again!
B: Yes, You haven't changed a bit.
A: Really? I feel my age.
B: Oh, no. You look fresh, and time has stood still with you.