Set this up with Black to move. White has Kg1, Ra1, Rf1, Ba2, Nc3, Ng5 and pawns on a3, b2, c2, f2, g2 and h2. Black has Kg8, Ra8, Rd8, Bc8, Nf6 and pawns on a7, b7, c7, e6, f7, g7 and h7.
The bishop on a2 looks down b3, c4, d5, e6, f7 and g8. Black's pawns on e6 and f7 stand in the way, and Black's king waits at the end.
Push ...e5 for space in the centre, and Bxf7+ follows. The king cannot take back, because the knight on g5 also covers f7, so White wins a pawn with check.
Nxf7 is stronger still. The king cannot take the knight either, because the bishop now covers f7, and the knight attacks the rook on d8.
Nothing about the bishop changed. Only a Black pawn moved. This is tunnel vision. Your eyes follow the pawn to e5 and the space it gains, so a bishop that has stood still for ten moves drops out of the picture.
Rooks do the same more quietly. A rook can sit on h1 all game until the h-pawns are traded, and then it owns an open file without having moved.