Success is measured in many ways.
Some consider happiness the ultimate indicator of a worthwhile existence. Others aren't satisfied unless they achieve a certain level of financial stability. Then there are those who require the appreciation and adulation of their peers.
Rock stars have checked off every one of those boxes - and then some.
It's why so many people want to be, or at least know, the guys who rock out night in and night out.
Thomas Scott McKenzie, a software project manager and lifelong hard rock fan from middle America, is among the millions who dreamed of wielding an ax in front of an arena or stadium full of adoring fans, a la Eddie Van Halen or Slash.
McKenzie took his rock obsession a step further, however, embarking on a cross-country expedition to meet and learn from the guitar gods of his youth - guys like Ace Frehley of KISS, Glenn Tipton of Judas Priest and Phil Collen of Def Leppard.
The result is "Power Chord: One Man's Ear-splitting Quest to Find His Guitar Heroes," an entertaining travelogue of sorts that hits all the right notes.
"Some guys want to visit every major-league ballpark," McKenzie writes. "Other people retrace their family's history through Europe.
"My mission simply had more ear-shattering volume."
And great anecdotes, too, including McKenzie describing the times he: shared a meal with KISS guitarist Bruce Kulick at a Cracker Barrel restaurant, attended a class taught by virtuoso Steve Vai titled, "Alien Music Secrets," and attended Rock 'n' Roll Fantasy Camp.
The latter tale is the highlight of "Power Chord."
You see, McKenzie is a top-shelf rock aficionado. He just isn't much of a rocker himself.
So at the fantasy camp, where wannabes shell out big bucks to form groups and learn from some of the best in the business, McKenzie had the misfortune of not really being able to play a lick.
Still, his bandmates were understanding, as was his camp counselor, bassist Rudy Sarzo, who played with Quiet Riot, Whitesnake and others.
McKenzie just wanted to have a few words with the men he has idolized ever since he joined the KISS Army as a boy growing up on a Kentucky horse farm.
Armed with a sense of adventure and determination, McKenzie tracked down - by any means necessary - his musical heroes, talking a little shop and even strumming a few chords in their presence.
That journey, which McKenzie proudly calls his "crazy guitar hero quest," makes for a fun read, regardless of whether you're a metal head like the author.