I suspect a lot of people are dealing with this realization right now. They've built a life around what we believe we're supposed to want - what we are told and what we believe will make us happy. But then they achieve those things and realize the contentment has yet to appear.
Usually we talk about this phenomenon in the context of advertising and consumerism. E.g. "I bought the $60,000 SUV / $4,000 handbag / iPhone 19 / 5br mcmansion / $3,000 suit but I'm somehow still not as happy or confident as the people in the ads? How can that be?"
For others, it can be "I finally clawed my way to the top of the corporate ladder" or "I finally have a home and a family" or "I finally finished my dissertation" and it's a mystery why they don't feel like they've arrived at that elusive feeling of satisfaction yet.
Two possibilities:
1) You always had enough to be happy and content all along. All you had to do was change the attitudes which were blocking those feelings. From pessimism to optimism, from scarcity mindset to abundance, from anxiety to meditation, from peer comparison to autonomy of meaning, from living in the past/future to living in the present, etc.
2) You adopted "wants" which were sold to you in popular culture, only to find out these "wants" did not fit you as a unique individual. E.g. you bought an overpriced house in a trendy neighborhood because everyone else was doing so, but it didn't make you happy the way it apparently did them. You got married to an opposite sex partner only to realize you have same-sex attractions. You watched that show everyone is talking about, and found it boring. You found that the problem with conformity is that everyone is different, and impossible to satisfy with the same things. Maybe in your special case what would really be exciting is a woodworking shop, or a pet goat, or a painting hobby, or a dominatrix, or a pond of muddy water full of catfish, or a collection of original sculptures by a forgotten artist, or a weekly volunteering meetup with friends, or a goldfish. Maybe in the pursuit of what everyone else is wanting, you forgot yourself, and you're tagging along on their boring journey.