I just discovered I like tormenting my neighbour

Yes, quite right. Treat them how you would like to be treated.
Our neighbour disliked us for over 20 years and blanked all of us. His wife died several months ago and all of a sudden he started to speak us in a very jolly friendly manner. We kept looking behind us to see if someone else was there.

Ha! I have a neighbour from hell for much the same reason - I think. How can you tell? This is a victorian terrace of only 5 houses and mine is the only council owned. "It" lives right next door and for some years after he moved in, we were sociable. Then we had the great gale of whenever it was, which blew down the garden fence between the 2 properties. He was told that he could ask the council to erect a replacement and in his greed, put in a claim for several thousand pounds for a brick wall to replace the wooden slat fencing. Needless to say the council refused and what was worse (from his viewpoint) they also investigated and pointed out that in fact, the fence was his according to the deeds and so he'd have to pay for a replacement himself!

You would have thought they had demanded the life of his only child.....

He refused to replace the fence for some time and it was not uncommon to go into my back garden and discover his elderly relatives sitting on deck chairs in his back garden, admiring mine.....it just became very, very silly and funny.

Eventually, I think because of his live-in girlfriends nagging, he replaced the fence but he has never spoken to me since.

A year or so ago we found a leak in the roof and when the council checked it, they found that a few tiles were missing. They sent along a crew of scaffolders who erected roof high scaffolding and told me that the roofers would be along shortly. A week later I was still waiting so I went to call the council, only for the 'phone to ring as I reached it. It was the council and himself next door had called them and complained that I had put scaffolding up ?!?!?

What, I asked, would I do that for? Out of a book? Nothing on the telly? I explained the situation and they apologised and sent along the missing builders.

That was the last time he made a formal complaint about me/us. I won't bore you with the others which were all just as sensible. He is now on record as being a "nuisance" caller and anything he does report to the council is ignored.

And he has altzheimers. I think he's had it for years and years and years.......

I loathe the man, have no sympathy for him and only want the satisfaction of outliving the b*****d so that I can spit as his coffin is carried away. If that makes me sound awful - well, I've never made it my life's work to make life difficult for other people, like he has. You reap what you sew, as my nan used to say.

That reminds me of my youth! Some people in our village were constantly annoyed by their policeman neighbour so every few nights they planted a for sale sign in his garden! He got so exasperated! Another toffee nosed woman who adored her horse and hated her neighbours and kept calling the council for nothing opened the door to the knackers yard people wanting to pick up her ‘dead’ horse. She shut up after that.

Compliment her when you see her. Someone was incredibly rude to me in front of a lot of people last year. I was actually vert hurt at the comments this piece of sh*t said, but I smiled and said 'Oh, I really love your shirt. It really suits you.' It was so not what he was expecting me to say or how I was going to react. He's never spoken to me again, but that's better than being rude! I always treat rudeness with kindness otherwise you're coming down to their level.

Greeneyedgirl I agree with you, it all seems a bit petty to me although I have to admit her behavior would annoy me too but in this dreadful time shouldn't we all be trying to get along?

I am getting along with her. I'm perfectly polite. Wouldn't it be worse if we both ignored each other. Then the dislike would have more space to seethe and expand.

Tell me about it. I have neighbours who smile and say hello when I am with my husband, but totally ignore me when I am alone. So I give them the deadpan look when they deign acknowledge me. I am not going to waste my smiles and my greetings on them - but I admire you for doing so!