There is one called Boots by English poet Rudyard Kipling. The poem is about soldiers marching, and in this case, it makes sense, given the context of why people are using the phrase and hashtag.

Anyone who has ever attended the US Navy's Survival, Evasion, Resistance, and Escape (SERE) school will never forget Rudyard Kipling's poem "Boots," according to SERE graduate and Navy veteran ...