I love watching my fish, some of the things they get up to is so silly. I really enjoy the tank maintenance, most of my fish like to interact with me while I am gravel vaccing. There are so many highs and lows with rescuing fish. Its really nice when I have had a particularly sick fish pull through and start enjoying life, or course there is the bad side then of those that dont make it.
The constant reading and research regarding fish care changes so rapidly, what you knew was the right thing 2 years ago is now totally wrong due to research and more people posing information. Its a never ending learning curve fishkeeping, you can become good at it, but never an expert.