Ah, the young. Here's how it goes.
20's: You think you need the best job, you are out on your own, you are working hard, taking some knocks, but holding on. Adventure!
30's: You start making some important career decisions for long-term goals. Many of your college buddies have moved on, and you meet others, but mostly less connected to others cause people your age are generally into their own thing by now.
Note: You will start to resent people in power at work who abuse that power, feel like you deserve more of a say cause you are more experienced in life. You may even quit your job and do your own thing. Also, you will start losing some of your sanity. This, as you will see, is a good thing.
40's: You are tired, but still kicking. You still feel good physically, but your metabolism will FINALLY slow down. Watch what you eat.
You will also find yourself admitting that you cannot believe you are still alive. And people of the same age will nod their heads agreeing, "Amen." You will realize that you have lost about 5-10% of your sanity, and that losing it is good because it helps you cope and laugh at the world. You definitely are WAY past taking ANY shit from anybody, and this makes it an EXCELLENT time to use your AGE card. "Um, I'm 45 and no you don't!"
I can't speak for the 50's and 60's and 70's etc, I'm only 46.