But I think I'm in earnest, and I do want something more than mere illusion.

但我认为我是非常认真的，我想要的不只是一个幻觉。

youdao

I'm in deadly earnest.

我是非常认真的。

《牛津词典》

You may laugh but I'm in deadly earnest.

你可以笑，不过我可是正经八百的。

《牛津词典》

"As yet I'm yet to go at it (social media) in earnest as so few people know about the elections, " he said.

BBC: Social media and the PCC elections: Tweeting candidates