Considering the later stanzas mentioning parents and grand parents also being "failed experiments" I feel as though the lyric
"Three cheers for my parents' lonely failed experiments!" could have a double meaning depending on its punctuation. The way it appears in the written lyrics is referring the children being their parents' failed creations, but if punctuated like so "Three cheers for my parents, lonely failed experiments!" it is making reference to their parents being failed creations as well. Looking at it this way you can see that the parents are failed experiments of their parents. And if you interpret it like me wherein this was intentional it's one sentence illustrating the children, their parents, and every other generation being a "lonely failed experiment" of the last. It exalts the beauty of human imperfection with "three cheers."
Considering the later stanzas mentioning parents and grand parents also being "failed experiments" I feel as though the lyric "Three cheers for my parents' lonely failed experiments!" could have a double meaning depending on its punctuation. The way it appears in the written lyrics is referring the children being their parents' failed creations, but if punctuated like so "Three cheers for my parents, lonely failed experiments!" it is making reference to their parents being failed creations as well. Looking at it this way you can see that the parents are failed experiments of their parents. And if you interpret it like me wherein this was intentional it's one sentence illustrating the children, their parents, and every other generation being a "lonely failed experiment" of the last. It exalts the beauty of human imperfection with "three cheers."