On The Sale of My Farm is one of Robert Frost's lesser known poems and was written before the height of his fame. It is the place he and his wife most cherished. Having farmed and later taught at a local primary school, Frost was eager to promote his life as a poet and would leave for England sometime afterwards. There is therefore, a theme promoting self-development and self-discovery as Frost is moving on to something new - "Well-away and be it so." As it represents a journey of self, the symbolism is intertwined with the theme and is to be found in the deeper meanings of the words and phrases.
Frost admits that he was not the most successful farmer and was perhaps somewhat reluctant in his efforts so "I...wish him all the gain/ I required of them in vain." Even if his farming was not his greatest achievement he loves the farm and will have to "unlearn to love" the home, the "Barn, and shed, with rat and mouse" as he leaves to chase his dream of becoming a well-known writer and poet. Frost however, lets the reader know that "It shall be no trespassing / If I come again.." as he intends to revisit the farm - perhaps when he is a renowned writer and he can reflect and will know that it was worth it. Metaphorically, the "grey disguise of years" combines both the journey - therefore the self-discovery - and the symbolism as he will be old (and grey).
The theme of self-discovery is evident throughout and there is a tinge of regret, a minor theme as Frost's son had died whilst they lived there and he may be "Seeking ache of memory here."