I have been three times to Bulgaria, within a few weeks! It might sound silly, but you meet cool be people here, hear about a festival there, you keep changing your plans, and here you go, three times in Bulgaria.
The first time was with a close friend, we have been to the seaside and to Sofia.
The second time, I was supposedly passing through on my way to Istanbul, but ended up staying 6 days in Plovdiv and then going to a bagpipes festival in the mountains (and then I went back to Serbia instead of Turkey)!
So the third time I was actually just passing through, and slept somewhere in the countryside just after the Serbian border.