Odds of Hanging On
If you're serious and this field intrigues and excites you, then getting the right education (and most likely lots of it) will be what sets you apart. And just like working in almost any other industry, complacency in your job will not help your case when someone younger wants to take your place—at half the salary.
In other words, this is a job where you'll constantly be learning, discovering, and re-educating yourself. Just keep moving forward and you'll do fine.