My Linnies are reasonably agile, but I think they've been flighted their whole life & had a reasonable amount of out-of-cage time, and it makes a difference - the desire to fly is instinct, the actual PRACTICE is learned behavior. For example, some parrots who escape & land high in a tree might WANT to fly down to their human, but can't figure out how - flying in a straight line is a different exercise than flying up or down. [The lesson: If your parrot is flighted, give it the opportunity to fly up high and come back down - if it ever escapes, it'll be a good skill for it to have, when they are ready to come back home.]