É uma frase de uma faixa na coleção " Humanos " de Mike Mills, conforme relatado em uma entrevista em Don't Panic :
At one point in the film, Oliver sprays in giant 3ft lettering "You make me laugh but it's not funny" onto a blank billboard, echoing a phrase on one of your Humans brand ribbon designs. It looks like you had a lot of fun with that, similarly the illustrations Oliver creates in the film...
It’s the line from the ribbon yes! That’s part of the crisis thing; for a long time it didn’t look as though I’d be able to make the film, so when it was green lit I put all these things that only I can do into it, my Humans collection, the graffiti I did and the drawings (especially the firework drawings). I felt like “this is my last film” or “this is the film I’m never going to get to do”, so when it went ahead I wanted to put as much into it as I could. As it took me five years to do the film, I started researching fireworks for Beginners and I got really into drawing them. I did a book on them for Nieves and that was published, and the slow process of the film kept going in the background. The same for another project where I hand drew a thousand rainbows and researched Gilbert Baker and the original 1978 Gay Pride flag; all the research set off these independent projects and I included these in there too, sort of like a ripple effect. There’s a lot in the film.
Com base nessa resposta, parece que não há necessariamente qualquer conexão com o resto do filme, apenas que o diretor estava tentando incluir muito de sua própria arte. Dito isto, eu não vi o filme, então certamente poderia haver outros pensamentos sobre isso.
Veja a faixa de opções em uma imagem:
O texto aparece na faixa azul, embora pareça ser ligeiramente alterado:
... u to know I don't think it's funny you make me laugh but I want you to know..