There are times in your life when nothing can seem to be more important than that one thing in your life: that job you're applying for, the big game, or that test coming up. You can win championships, graduate from school, or make your first million dollars. Heck, you can get that bike you wanted more than anything for Christmas. No matter what it is, it can be your most prized goal, accomplishment, or possession in the world. As a result, it can seem in the moment like nothing could ever top it.
But life changes. When you pass that difficult entrance exam that you studied months for, there will be another test that's just as important to you in a few months. If you get married, you might "let yourself go" or take your spouse for granted over time. If you win a championship, you might set your eye on another one. What matters to you in life is subject to change at any time as your thoughts, beliefs, and perceptions change.
A famous example is Mike Tyson, who is considered to be one of the best boxers of all time in his prime. In an interview years later, he said that the championship belts meant almost nothing to him, that they were just a worthless trinket to him, and that his most prized accomplishments were his children growing up to be healthy, successful adults. This person grew up a fighter and channeled a childhood of anger and toughness into boxing to become the best in the sport, and years later he doesn't even regard his biggest accomplishments during his career that highly.
This could be good or bad news for you, depending on how you look at it. On one hand, you might like the idea that no matter what happens to you in life, "This, too, shall pass." On the other, you might wish for moments to last forever and hate that, "All good things come to an end." In any case, the things that matter to you as a child will change as you grow into an adult, and what matters to you at the end of life will be different than your early adulthood.
This is an evolutionary biological necessity and not just a philosophical trope. If you ate food and felt great forever, you would die when your body became hungry next and didn't signal you with a hunger sensation. If you felt passionate love forever, you would never calm down enough to raise children and remain a responsible adult. If you kept the one thing you accomplished as the biggest thing ever, then the rest of your life will seem paltry in comparison. But, of course, it's not. You just have new priorities. Your children's first steps can be as eventful as winning the Super Bowl. Your 50th wedding anniversary can be as significant as your wedding day. Your new bike can be usurped by your new car, your new house, and your child's car or college education. Your body acclimates itself to its new state and then prepares you for the next growth opportunity in your life. If you couldn't adapt to new conditions, you couldn't continue on your life journey.
So your priorities will change, and that's okay. It's good for the most part to lean into them, as you will have new emerging priorities and old priorities will fade away. Little league games, video games, and homework will give way to college exams, relationships, and part-time jobs, which will give way to promotions, big projects, and familial responsibilities. This is a signal that your life is continuing to evolve.
But sometimes you don't actually want a feeling to fade too much. Yes, you might not be able to relive the magic of hearing your favorite all-time song for the first time and might have to listen to new music for that dopamine hit, but you will want to appreciate your spouse for a lifetime and so need to sustain feelings of love and gratitude. In these cases, you need to practice gratitude by taking the time to remind yourself how great what you like is. A spouse, children, a car, a job, a house, friends, family, or even just your health. While you can get used to anything being a certain way in your life, that doesn't mean that you have to forget its value and importance to you.
While you can't preserve the initial feelings from the first experiences with a person, place, or thing, you can always retain the affinity for it by remembering those feelings and reciting what you like about it. Yes, you need room for the next growth opportunity in life, but that can be built on a foundation of things you appreciate and so you don't have to ignore or abandon what has helped you get where you are. The "Let the past die; kill it if you have to," quotation from the Star Wars sequel trilogy might've been referring to letting go of things holding you back, but it definitely doesn't apply to things that are of continuing benefit to you or are obligations that you have committed to via social contract (e.g., familial obligations). Your holding of the significance of something in your life as it changes will ensure that those bonds don't die, your memory of who you are and where you came from won't fade, and your life won't lose its significance in your own mind.
Of course your priorities, preferences, and beliefs are always subject to change, and that's fine. Just make sure that you both enjoy discovering new passions, interests, and life directions while preserving what you love about how your life has progressed so far so that you have a foundation to build from. It will serve you to appreciate what you have and desire the next adventure, as everyone needs to both push themselves forward, get support when they need it, and rest and recover in between bouts of effort. If you know when to let something of diminishing significance go, sustain things you are taking for granted, and reduce the significance of something that you think is important now but won't be later, you will have mastered the art of focusing on the right things in life.
Side Note: A related topic in economics is called "time preference"—referring to how people prefer to have everything now. It's the person who can lower their time preference so they can plan for a better future through saving, investments, etc. now who will experience a more prosperous future. So the more you can diminish the significance of your seemingly urgent temptation now so that you can put off that purchase, stop procrastinating, or prioritize the better long-term action, the more you will succeed in life. While this post was focused on how life will inevitably change what's significant to you, I thought it was worth mentioning in this post as a footnote how there's science and value behind controlling what you deem to be significant enough to give your time, attention, and effort.