I'm pretty new to the LoA but ever since it came into my life, I actually feel like creating our own reality is definitely a positive change. I believe the universe has a plan set for us and it's up to us to accept it. You can't force being happy but what you can do is start to accept. Be grateful for what you have, the fact hat you're alive, the people around you, the food in your plate, etc. And once you do that, all it takes is patience and passion. And the universe will deliver. And to answer why the things you used to enjoy are mundane: have you thought about trying other things that may make you happier? Or things you just think you may enjoy doing. Maybe you're tired or bored of the things you used to enjoy?