Fixed my own toilet!!!!

For (at least!) the last two months we've been living with water hammer.
Since mid September we've had the drone of water hammer every time the loo was used. Having a handyman as a husband, my wife should have been able to expect the job to be done immediately. Why has she been waiting for so long? I hear you cry. To be honest I have no idea! It's bugged me since it started! The drone was terrible. It just went on and on.
We were having a lie in this morning/afternoon and all of a sudden I decided to fix it. So there I was, on a peaceful Sunday, in my lolly gaggers, head under the cistern, replacing the defective ball valve. It only took a few minutes and the job was done.
What I still can't figure out is why it took so long for me to get around to it. . I knew what the problem was. I had the parts in the van. I had the tools to hand. I knew it would only take a few minutes. So why oh why did it take so long? Can any one tell me?