Be aware tho, that your mind is a very powerful tool and when you think about something or something you create corresponding emotion. Its not that the guy is strong on your mind, its you making it so. This can be a double edged sword..
Yes this has happened to me many,many times. Once I remember thinking about my mum's cousin and within a very short time (I think it was the next day) I received a letter from her. The thing is our thoughts are electro- magnetic: they draw whatever we are focusing on towards us. I like to think of it as a kind of invisible telephone line between me and that person.
Oh,and another thing I've often noticed is if there's someone I really really want to avoid and I'm all nervous thinking about how I hope to God that I don't run into them....they're the exact person I bump into. I remember when I was a teenager my friend and I decided to bunk off school and get the metro into central London for a fun day out. All the time I was a little tense, hoping I didn't bump into my parents or get discovered. On the way to the station my dad passed me in his car (luckily he didn't see me). The second thing that happened was that on the way home my friend and I got into the train and sat down and to my horror I found myself sitting opposite my mum,who was returning home from work. I had to think up a good excuse really quick. Hahaha. I guess my fear of being found out actually attracted that outcome to me. :-)
If you think ' I hope it doesnt rain ' , the universe registers one word ' rain '.
Next time you want to avoid somebody, simply exclude him from your thoughts :)