I think that the sense of what Mr. Stallone is saying is more to the effect that life itself is insane, and interspersed with only short periods of sanity. We who are living, then, struggle everyday to hold onto those periods of sanity, and not stay too long in the insanity that characterizes most of what life is. Interpreting it this way, Stallone's statement would communicate an element of dubious reassurance to Poe that, hey, don't feel you are alone, by becoming insane you have only discovered what life is really all about.
An interesting part of Stallone's statement, if you look at it very closely, is the word "horrible;" he calls the times, or "fits" of sanity, horrible. This might imply that he thinks the "fits of sanity" are ironically not much better than the times of insanity, perhaps because when one is sane, one sees how awful the other part of life, which is insane, really is.
I think in looking at the statement, one has to remember that, unlike a poet's work, which is characteristically carefully thought out when rendered (although I know it can be argued that this is not always true), a tweet is a more spontaneous expression of what is on one's mind. It may be that in analyzing Mr. Stallone's tweet so closely, one might be ascribing meanings and motivations to it which are not really there.