seeker242 wrote: [meditating with no goal] simply means that when you actually sit down to meditate, you aren't preoccupied with some other thing besides the meditation or meditation object itself, which takes your attention off of the actual meditation you are doing right now.
This is really the essence of it. Meditation might make you happier, but at least initially, it more likely will show you the obstacles that are preventing your happiness, and give you the freedom to change those. If we sit and want X, Y or Z to happen and it doesn't, we get easily frustrated and lose sight of what we're actually trying to do--that is; develop a deeper understanding of the three characteristics.
I've found it really helpful to stop thinking about goals and start thinking in terms of 'direction,' keeping in sight the end of the road, but focusing more on the steps I need to take right now.
Trust that your meditation practice is doing what it should, don't get frustrated if you have weeks or months where you feel crummy (you'd feel crummier if you weren't meditating!) or you can't seem to focus (you'd focus worse if you weren't meditating!). Just keep moving forward, one sit at a time, one breath after the other.