What does the phrase 'veteran bores' mean?

In the The Great Gatsby by F. Scott Fitzgerald, there is a sentence, 'In consequence I'm inclined to reserve all judgements, a habit that has opened up many curious natures to me and also made me the victim of not a few veteran bores. '
what does 'veteran bores' mean? a very boring old soldier or just a very tiresome person? thx you all.

Veteran implies experience. So in effect what he is saying is that, because he doesn't automatically dismiss people by appearance and will talk with them to find out who they are, what they are about, he has often found himself talking to people that are quite adept at being completely uninteresting.