Careful, These Are Gateway Factoids
Since horseraces start when a gate is opened for all the horses simultaneously, the term “right out of the gate” is used for something that happens right at a commencement.
The popular notion of the “pearly gates” to heaven actually comes from the Book of Revelation, which describes 12 gates made of pearl (one pearl per gate) leading to New Jerusalem.
Since floodgates are typically solid barriers which hold back would-be floodwaters, to “open the floodgates” means to allow many previously-impossible things to happen.
Ever since the 1970s, scandals of all types are often given names ending in “-gate.” This traces back to Watergate, the major political scandal in which burglars were caught in June of 1972 in the Democratic National Committee headquarters at the Watergate Hotel in Washington D.C., tapping phones and stealing documents. The intruders were ultimately traced back to President Nixon, and despite his attempts to cover it up, the scandal ultimately led to his resignation in 1974, before he could be impeached.
According to Dante’s “Inferno,” the gates of hell bear the famous inscription “Abandon All Hope Ye Who Enter Here.” On this mortal coil, however, the Darvaza Gas Crater in Turkmenistan also bears the nickname “The Gates of Hell” since this huge open pit has been burning in the desert since a Soviet drilling rig accident over 50 years ago.
The term “barbarians at the gate” has been used in many contexts to describe a nearby hostile force, but it originally came from the Goth’s sack of Rome in 410 AD.
“Crashing” a party or even means to show up uninvited, but it is a shortening of “gate crashing,” which means the same thing.