Why are these H the most acidic?

I don't quite understand why these two hydrogens are the most acidic. From a hybridization perspective, these are connected to a $$\mathrm{sp^3}$$ carbon (I thought the more s character, the more acidic). So why is it not any of the other hydrogens (connected to $$\mathrm{sp^2}$$ carbon)?

• Consider the structure of phenol, how stable is the phenoxide ion? – Waylander Oct 4 at 7:27

As you can see in the given figure that after abstraction of $$\ce{H+}$$ the conjugate base can resonate to attain aromaticity. It is this stability that makes the hydrogen atom acidic. Now to remove the second $$\ce{H+}$$ the story changes, but I would be leaving out that discussion as it has not been asked in the question.