I understand that according to Masechet Brachot and the normative halacha, in certain cases, one who unintentionally missed saying a prayer service may "make up" that service by reciting the Shmoneh Esrei twice in the next service (Tashlumin). I know that there are many laws about exactly what to say and in which cases this opportunity exists, and whether this applies to the recitation of the Shma, and I know that even in the gemara, there is a discussion of whether this entire concept is actually efficacious or whether missed opportunities are missed.
But what I don't get is why this would ever be an option at all.
If we miss an obligation to perform a mitzvah, why would one think that we can "make good" by doing the mitzvah twice later? It isn't the case for lighting candles (though I know some women increase the number of candles they light permanently if they miss lighting on a Shabbat), and I can't think of another mitzvah where it IS the case. If I forget to bentch, I can't bentch twice after my next meal. If I forget to give matanot le'evyonim on one Purim, I can't give twice the next year. If I don't put on tefillin today, to I put them on twice tomorrow?
Why should there be a chance to make tashlumin, and why would it only be for Shmoneh Esrei? Is it just because "the gemara says so" or is there an underlying rule or logical principle involved?
Note -- I see this as related to, but not a duplicate of What does it mean to make up for prayers unavoidably missed - Tashlumin? because I see that question as based in the understanding of "Tashlumin" as "making up" whereas I see it as "completing an obligation" so I am less concerned with the object to whom one "makes up" and more with the notion that we can "complete" a mitzvah at some other time by doing it twice in any situation.