How do I mame my story longer, by dragging on with words...?

My question obviously doesn't make much sense, but it was the only way I could think of. I'm writing a story in a first-person POV; I have the whole story outlined, but the problem is that...I always get to the point immediately. By this, I mean that I always sum up my whole chapter in only three pages, and I find there's nothing much to add. I want the character to have a lot to think about, so that there's more to the story, although I want his thoughts to be interesting to read, and not boring. You get the idea...how do I keep the flow going, without getting to the point too fast?