What's meant to be will be

So if it's meant to be it'll happen right? But what if it's not meant to be? Do I continue waiting for something to happen or better yet, even chase after it? It's nonsense lah really... Why is it never mutual? It just seems like nothing ever goes my way and I'm just so tired of it all... So if I believe in that saying, should I just let go? Because if it's like this, then what's not meant to be will never be, right?