cornerstone syndrome

when you miss someone so much that you start thinking that you've seen them around, but really it were just a look-alike. severe cases of cornerstone syndrome would be to actually pretend that the look-alike was the person you missed.

sometimes if you missed a girl you might even shag their sister...

"i thought i saw her in the battleship, rusty hook AND the parrot's beak but they we're all just look-alikes"
"you must have cornerstone syndrome"