I agree with getting older. Once I turned 50, I had no fucks left to give.
There are people whose good opinion I value, and I will go out of my way to help them out. The rest I cannot be arsed with. From MN I have learned that 'no' is a complete sentence.
I had a couple of lightbulb moments in my 40s...a NDN came onto my property with his builder, ignoring me watching them and proceeded to confer about something in the back yard, then left. The next night he came back demanding that I move both my oil tank and shed as he wanted to access the barn they were placed against. They were there when he bought his property, as we had lived there longer. I was about to agree, when I realised he was trying to intimidate me, so I refused to engage, and said no. He huffed and puffed, demanded dh's work number and email address, and demanded to speak to him. As he worked in Brussels, this was not going to happen.
I conferred with dh later, and the response to the neighbour was if it is possible to scaffold round the conning tower of a nuclear submarine, then your builder can scaffold over my shed and oil tank. End of discussion, and please, next time, ask if you wish to access my property, as otherwise I'll call the police as you are trespassing. I felt quite empowered!
The next lightbulb moment was when mil revealed her true colours and I realised that she had been manipulating me for 25 years. That soon stopped and I haven't spoken to her since 2013.