Growth varies across life stages
As we age, growth and learning require more intentionality
Growth looks different across stages of life. If you feel like learning is harder than it used to be, you're right. As an adult, it takes more intention and effort.
Throughout K-12th grades, you're in a very structured environment. If you do what's expected, you move up one grade each Fall. Some kids get held back; others skip grades. But the vast majority advance at the same pace. There's plenty of handholding to keep you on track.
Yet even if you put in zero effort, you still grow and develop. You get bigger, stronger, smarter, and more capable. It's not by choice. The default is growth.
In college, there's still structure to guide you. Your major has a set curriculum and intended trajectory. There's some handholding to help you graduate "on time" - traditionally, four years. But if you take longer, that's fine in most cases. People advance at different rates, since it's based on units completed and not age.
Beyond the classroom, you grow as a person. You figure out what it means to be a young adult - to make your own decisions and develop your own views. Growth is not the default it was in childhood. But it's likely to happen in response to your new freedoms and duties.
After college, however, there's little structure or handholding. It's up to you to define, make, and measure progress. Growth is no longer the default - either on or off the job. At some point, you stop developing personally or professionally, unless you choose to do so.
Some would say that if you're not moving ahead, you're sliding backwards. For example, if you stop working out, you will lose muscle mass. If you stop practicing your craft, you will become rusty. If you stop learning and challenging yourself, you will stop growing.
To be clear, it may not be easy. Learning languages, physical activities, or new technologies - in particular - may prove more difficult as you get older. Some days it may feel like two steps forward, one step back. You may take longer and make less progress.
But you will also appreciate your progress more than you would've when you were younger. You will find that growth is still worth it.