perplex

verbs

be a mystery or bewildering to
"This beats me!"; "Got me--I don't know the answer!"; "a vexing problem"; "This question really stuck me"
amaze, baffle, beat, bewilder, dumbfound, flummox, get, gravel, mystify, nonplus, perplex, pose, puzzle, stick, stupefy, vex
make more complicated
"There was a new development that complicated the matter"
complicate, perplex