The description of social contract does not imply that it was signed by me

As Hume called it, a convenient fiction. It isn't how any government came to be, and a contract imposed under threat of force isn't valid anyway.

I'm reminded also of that meme cartoon with the annoying person coming out of a hole and observing the suffering citizen is still participating in society, "how interesting".

Which one? Hobbes's, Rousseau's, Locke's, or Spencer's? Generally, these so-called contracts are morally fashionable bandwagons attempting to appeal to some vague authority. They lack at least two elements that make a contract in the proper sense of the term: mutual consideration and clear, well-defined, promises of fixed duration and scope. There's no contractual obligation to keep a society "alive" indefinitely and for its own sake anymore than there was one to keep the British Empire in tact.