The Government of Canada's official website to apply for an eTA. It only costs $7 CAD. Most eTA applications are approved within minutes of applying. New entry requirement now in effect: visa-exempt foreign nationals who fly to or transit through Canada need an Electronic Travel Authorization (eTA). Exceptions include U.S. citizens and travellers with a valid Canadian visa. Note: The leniency period that allows travellers to board their flight without an eTA ends soon. Be prepared: Apply for an eTA before you book your flight to Canada. Most applicants get approved within minutes.
The brain is fully developed around the age of 20-25 like the above say. But making rational decisions has nothing to do with that, you can make those at any age. At about age 23 the final stages of brain development occur. The last part of development to occur is the part of the brain that is involved in rational decision making.
Between the ages of 10 and 25, the brain undergoes changes that have important implications for behavior (see Cognitive development below). The brain reaches 90% of its adult size by the time a person is six years of age. Thus, the brain does not grow in size much during adolescence.