I sincerely am so curious as to what you get out of this experience. If you know that you won't speak with him, why stalk him? I am really trying to understand how this process works for you... what are the benefits vs risks?
I'm not calculating benefits vs risks in that situation. And, in fact, there are no risks whatsoever. I could just go say hi. If it doesn't work out, so what, we weren't close anymore anyway. If it works out, it's a nice reconnection.
It's just extremely awkward. What should I say? He does often serve customers as well, so if I talked to him, a waiting line would form behind me. That's the easy way out of the conversation ("gotta go, you seem to be busy"), but then I'd feel like a fool... talking so little after so many years. I could, of course, ask if he wanted to meet later on a better time, but would he even want that... I mean... suddenly... after so long time ago... I'm just thinking the situation through from his possible perspectives as well as my own. Basically it prevents me from acting.
And, I actually don't know will I ever talk to him. I plan to do it every now and then just to get it out of my system. I just don't know whether I'll really do it this time. And I don't necessarily stalk him that much; I occasionally go there for mere shopping as well. I have to be careful not to be seen by him, though...
Also, I presume you do this with women as well? If so, which feeling is more uncomfortable: speaking to her or beating yourself up about how you didn't speak to her?
I don't change my behavior depending on the other person's gender, but if you mean whether I act the same way with romantic contacts, then... yes and no. Every situation is unique. Sometimes I'm very straightforward, sometimes I'm everything but that.
Whenever I let something become a long cycle, it kind of feeds on itself and breaking the cycle is difficult. If I had gone talking to my friend early on, it would have been much easier than it is now years after.