You're going to get passed by those who are younger, hungrier, or just plain working harder than you are.
Not only is your experience not enough to keep you in the lead, there are many other factors as well.
To use my son as an example once more, I figure when he was born, it took me about 20-beers to be less competent than him. Now, he's probably able to navigate through life better than me on only 10-beers. Pretty soon, if I'm only 3-beers off being tack sharp, he'll have me beat for a lot of things. And then one day, he'll have a few beers and realize that he's being out-witted and out-performed by his six-year-old son. We all get surpassed. (And no, dear, I've never had 10-beers around our son, it's just a metaphor!)
Don't forget to check your rear view mirrors and don't do anything to someone while you're in the lead that you'll regret when you're looking at their tailpipe in a few years.