Hop on Pop by Dr. Seuss
I must have been five or six years old and I remember vividly playing school in the family room of my parents home and actually understanding that the letters “p - o – p” joined to create the word “pop” and that stood for the father figure in the book.
I am still impressed by the timelessness of the work. Dr. Seuss created so much content with such a small vocabulary. Truly amazing!