I'm sorry to break this to you, in an e-mail from a random stranger like this, but it needs to be said: Most of your life won't be fantastic. I'm not joking. The adventures you'll tell your children about will be a minuscule part of it. So if you want to avoid the feeling of utter disappointment as you grow older, you need to accept that fact. Sorry.
This leads us to the insight: You should focus more on the non-fantastic parts. The parts where you eat breakfast, walk to the bus, have a boring day at work, eat your ordinary lunch, shop groceries, and brush your teeth. After all, this is the major part of your life, and neglecting it is a wasted opportunity.
Here's the thing: Most of the boring stuff in your life is so dull, that even the tiniest thing can make it seem fun. The tiniest thing. This means the you could make it better with extremely simple means.
What exactly am I talking about here? Little things. Like these:
* Challenges: When brushing your teeth tonight, use your left hand.
* Mind games: When you enter work (or school!), imagine the sound "Kabaaaam!" as you enter, as if your presence changed the whole room.
* Action: Jump down from the side-walk, instead of just stepping down.
* Changes: Buy some fancy tomato sauce tonight, instead of your usual brand.
* More action: Count the number of pink things on your way to work, as if your life depended on it.
See? Easy stuff. I really try to live by this "Everyday Action" idea, and I think it works for making the boring parts of life more fun. Because that's the thing: just because the fantastic moments are few, there's no reason to just sit there, waiting for the next big thing to swipe you off your feet. Have some fun meanwhile, it's easy...