Calm ALL the time is a pipe dream.....life is stressful......part of the key to being "chill" is to realize that there are just some things that are always going to be beyond your control so you shouldn't waste time worrying about those things......concentrate on what you can control and go from there....8)
No one can keep calm ALL THE TIME. Humans normally get nervous, panic, etc., once in a while. Some more than others. But whenever you want to calm yourself, all you gotta do is think positive and relax. Breath in and out. Clear your mind and concentrate on what you gotta do now.