Those dreams you had as a child most likely can still happen. Sure, it takes willpower, discipline, commitment, work but they’re as alive as you allow yourself to be.
So instead of thinking I’m 40 years old, I won’t study and retire from being a brain surgeon by the time I’m 65, readjust your goal. Some things take time and that’s what makes them worthwhile. Growing and gaining understanding of what you want and how long it will take you to get there realistically makes it easier. Set smaller milestones rather than one, big goal that you know you want to achieve it, but you can’t really see it happening.
Look at the areas of your life that you haven’t reviewed in a while. Is your body in the best shape it can be? How about your diet? Your circle of influence? Your learning process. When was it the last time you’ve exposed yourself to new ideas? Goals are a fun way to measure our success, make them work in your benefit.