Across the armed forces, the minimum age allowed for enlistment is 17 (with parental consent) and 18 (without parental consent). The maximum age for enlistment for someone who has never served in the military before varies by branch; for the Army it's 35, for the Navy it's 34, for the Air Force it's 39 and for the Marines it's 28.
The year of the horse means there is leadership associated with this sign this year, so your authority may increase, according to Ng. However, the impulsive behaviour of the horse can lead to recklessness, so stay away from gambling and speculations.
The word pony derives from the old French poulenet, meaning foal, a young, immature horse, but this is not the modern meaning; unlike a horse foal, a pony remains small when fully grown. However, on occasion, people who are unfamiliar with horses may confuse an adult pony with a foal.