Question

That's the topics you started.

It looks more like the number of THUMBS UPS" given to me.
Does not agree with my number of topics.

It indicates total thumbs up received on the topic.
One thumb is given when you create a topic or make a post.

As others add their response, the thumbs increase.

The down side (isn't this often the case?), comes when someone decides to vote a thread down. It's not necessarily a personal reflection on you. It tends to be done to hide topics the person is not interested in. Get enough of those and your thumbs drop to 0. Unlike posts within threads, it won't go any lower.

For example: if you make a post on nuclear weapons, someone with no interest in it, might thumb it down.

Oh, sorry, read the post too fast. Yes, it's the aggregate votes on the topic.