Try reading here:
http://www.spiritual-path.com/numerology.htm
There are other sites that explain in different ways, but see if this one resonates with you.
I think the key might be to try to remember exactly what you were thinking about when you see the 1111s. You need to be "aware" of your thoughts. Or if something happens at the same time of the 1111s.
I got these numbers some 2 to 3 years ago. It first started when I was running into the same person each time I saw the 1111s. It took a while to figure it out. And I began "communications" with my Spirit Guide for the first time at the same time. (I didn't even have any knowledge about these things at the time. This forum helped a lot.)