The biggest similarity between "When You Are Old" and "To the Oak" is that they are both love poems, expressing feelings and thoughts about love.
"When You Are Old" is a love poem written by Yeats, which expresses his infatuated love for the Irish girl Maud Gunda. The poem depicts the contradiction between time and love and expresses It expresses the author's regret for the passing time and unsatisfied love.
"To the Oak Tree" is a love poem written by Shu Ting, which expresses the independence of love and the pursuit of self-worth. The poem depicts the relationship between one tree and another tree, expressing the author's The noble pursuit of mutual respect and independent love.
In short, "When You Are Old" and "To the Oak" are both classic love poems, expressing the author's different understanding and pursuit of love, and embodying the true meaning of love.