Its an analogy, not an invention. Im perfectly aware of how the system works.
Then you already knew that the concept of "paying back taxes" is a complete fiction, but tried to invent a flawed analogy to make yourself feel better. You may be fooling yourself, but not anyone else.
My point is, a system like that (people pay into a pool of money or an organization so other people can receive help from that pool of money or organization, who are then required to pay into that pool or organization in turn), if managed properly, can work very well, for the benefit of many individuals and the economic strength of the organization or group in question.
That doesn't describe any of current government income transfer programs. Any benefits received do not result in a require for future taxes to be paid. And any taxes paid now or in the past do not legally obligate the government to pay any future benefits.
For instance, if you think your Social Security tax payments create a contractual obligation to pay you benefits, you would be wrong. See Flemming v. Nestor. If you don't believe my interpretation, maybe you'll believe the Social Security Administration:
http://www.ssa.gov/history/nestor.html
Entitlements are subject to Congressional authorization. The law could be changed at anytime. And if it's not, Social Security is currently authorized to spend no more than it collects in taxes, once the Trust Fund is exhausted around 2033. Current projections say that revenues will only be able to pay 75% of the benefits that retirees are expecting at that time.