Cockateils are GREAT pets, but they do some things that may be problems for some people.

as chrissycat21 said, teils can live over 20 years. my cockatiel, Lucy, turns 19 this march. he probably still has a few good years left. before buying a teil you have to think if whether your going to be there for the bird that long.

the cockatiel can't stay in his cage all day. teils need outside the cage time a MINIMUM of an hour a day. birds are super smart. they need time out of the cage to strech their wings, explore, etc.

teils can also be preety loud. Lucy starts his whistleing at about 8-9am every morning. it can be hard to sleep through the ear piercing whistles and screams.

i advise you to get some cockateil books and read up on some websites. there is so much to learn about the birds before considering buying one. GOOD LUCK!