One should not depend upon a favorable (and typically overoptimistic) outcome to one's plans until it is certain to occur.

(nonstandard, dialect) themselves

Obsolete form of they’ll.

(nonstandard) themselves

(informal) Contraction of they would have.

(African-American Vernacular) Synonym of their

(dialect) Contraction of they (third-person pronoun) is. / (dialect) Contraction of they (=there) is.

Turbulent changes do not affect reality on a deeper level other than to cement the status quo. / A change of heart must accompany experience before lasting change occurs.

(colloquial) Expresses skepticism toward a hypothetical argument by another.

The larger or the higher of a rank something is, the more disastrous and spectacular its downfall.