Enlarged lymph nodes

Does anyone else just have enlarged lymph nodes , and nothing you can do make them shrink or go away? When I was about 15 I had a root canal on a bad tooth, and the lymph node under that tooth in my neck was enlarged, and since then never changed size. I have brought it up to my Dr a few times, he always says it’s nothing to worry about. It does not bother me or cause any pain or irritation, I just find it odd?