It's Not Too Early or Too Late
You have to continue to differentiate yourself at each stage in your career. Regardless of your age, at every point in your life, there is a younger person eager to step into your job. If you are 30 years old, there is an impatient 20-something coming up on you; at 40 there is that pesky 30-year-old. One 60-year-old CEO told me about a 44-year-old knocking on his door to take over the company—his own son!
The problem is that you, like others, had the impetus to "do something" and "be someone" when you started your career, but then the realities life set in with marriages, children, divorces, debts, illnesses, and career hiccups. Then someone "sped up the clock" when you weren't watching, and now a bleak picture frequently pops up of you aging fast in an outdated building, lined with long rows of gray cubicles, and you are pushing paper and working in a mundane and mind-numbing job, with no excitement or significance.
Put all that real life together, and it can become a little discouraging. It could make you question yourself or even give up, disengage, chuck it all, and drop out. But you can't because you have responsibilities, pride, dreams, hopes, and the need to prove to yourself you do have it in you to create an extremely meaningful personal and professional existence.
When you want something you've never had, you have to do something you've never done. Whatever your age, job situation, work history, or family way, turn up the juice going forward. Do it now, do it for your team, your company, and yourself—that is, unless you are ready to give up. But if you are like me, you aren't about to give up. You must realize that personal reinvention never ends whether you have a little gray hair or no hair.