By the age of 30 some of these guys and gals have got "there", and have run out of steam. There is nothing left to strive for other than more pay for less work/ better T&Cs / less distance to walk between crewroom and a/c / better car park etc etc etc!!
Flyingstig, how true!
Have you ever reached a goal and then thought "Now what?"
Success without fulfillment is failure. Dreams and goals are important but I believe it's who and what you become on the way to them that is more significant. Enjoy the journey!