I learned about the equilibrium constant. Now, I've seen that the equilibrium constant of burning is extremely small $(K \ll 1)$. here, I have a question. you see, $K$ is still NOT 0, which means that the forward reactions happen at least a tiny bit. Then, shouldn't we see some parts of anything burning at least a little bit?
shouldn't I be able to observe this tiny bit of combustion happening at room temperature? if $K$ is extremely small but not 0, I don't understand it.

In general, I've always wondered why we don't see small amounts of reactions happening spontaneously since the equilibrium constant isn't 0.

There's the concept of a "threshold energy", but it seems a bit arbitrary and not well-defined.
Why is it that when I use a lighter, for instance, that things don't catch fire spontaneously all around me? Shouldn't the equilibrium constant $K$ for the carbon combustion be big enough for that to occur? I was told that I could calculate the amount of fuel needed for a car engine, assuming that everything burns completely and at constant pressure, knowing $H$ (enthalpy of combustion) and $K$ and by