I don't think anyone can be convinced to become vegetarian, it's something you figure out for yourself. In my case I was eating a bacon sandwich in a Wetherspoons at breakfast. Some posh guy came on the television (sky news was on) and he was wittering on about how fox hunting is actually good for foxes as overpopulation of foxes can lead to starvation. Obviously that sounded utterly ridiculous to me, there are more efficient forms of killing than getting a dozen posh people on a horse, a few dozen dogs, some silly costumes and then racing through the woods. It was clear to me that this was an individual who was murdering an animal for pleasure, it was fun for him.
I was pretty angry about this, when I took another bite of my sandwich I realised that I was doing essentially the same thing. Not as directly malicious perhaps but wasn't I facilitating in the murder of an animal for pleasure? I could survive without meat so it wasn't something I needed, rather it was something I was doing for pleasure. I felt deeply disturbed that my own behaviour could be comparable to that of someone who murders animals for fun. Although fox hunting is a great deal crueller than eating meat I just felt there were too many parallels so I stopped there and then.