It was hard to believe that the narrator’s grandmother was once young and pretty. The very idea was revolting. She had always a wrinkled and pale face. She looked the same terribly old lady for the last twenty years. No change was ever visible in her. The narrator had never seen her being young and pretty.

The grandmother looked very old . Her face was full of wrinkles. The author has seen her in this condition very since he was a child .So it was difficult for him to believe that the grandmother was once young and pretty.

Introduction:
The author found it hard to believe that the grandmother was once young and beautiful due to several reasons. This disbelief stemmed from the stark contrast between the grandmother's current appearance and the idea of her being young and beautiful in the past.

Physical appearance:
One reason for the author's disbelief was the grandmother's physical appearance. The author describes the grandmother as having a wrinkled face, gray hair, and a hunched back. These physical attributes are often associated with old age and are in direct contrast to the image of youth and beauty. The grandmother's aged appearance made it difficult for the author to imagine her as ever being young and attractive.

Lack of evidence:
Another reason for the author's disbelief was the lack of evidence or visual cues that would suggest the grandmother was once young and beautiful. The author may not have seen any old photographs or paintings of the grandmother during her youth, which could have helped in visualizing her in a different light. Without any tangible proof or visual references, it is challenging for the author to imagine the grandmother's youthful beauty.

Generation gap:
The author's difficulty in believing the grandmother's past youth and beauty could also be attributed to a generational gap. The author and the grandmother belong to different generations, and the author may have a limited understanding of the grandmother's life experiences and personal history. The author's perception of the grandmother may be influenced by their own experiences and societal norms, making it harder to envision the grandmother as anything other than old and frail.

Emotional disconnect:
Lastly, the author's emotional disconnect from the grandmother's past could contribute to the disbelief. The author may have only known the grandmother in her old age and may have never witnessed her youthful vitality firsthand. Without a personal connection to the grandmother's past, it becomes more challenging for the author to imagine her as young and beautiful.

Conclusion:
In conclusion, the author found it hard to believe that the grandmother was once young and beautiful due to the stark contrast in physical appearance, lack of evidence, the generation gap, and emotional disconnect. These factors combined to create a barrier in the author's perception and understanding of the grandmother's past.