What are all excellent reasons for joining the infantry?

Can you give me some reasons for joining the Infantry please, I'm 15 and gunna join basically so I can fight and you don't need any qualifications but I'm not gunna say that incase he thinks I'm nuts. But what are good reasons for joining except to lead a life of discipline ( so fake for a 16 year old to say that one haha ) and patriotism cos I'm a Brit we don't have Patriots really.