Why do fish think K7o is always the nuts?

Seat 1 is the button
Total number of players : 6
Seat 2: Shook_Foil ( $400 )
Seat 3: dutchboy2333 ( $1030 )
Seat 4: spector2 ( $459.30 )
Seat 5: HERO ( $1025.91 )
Seat 6: Freewheelinn ( $576.50 )
Seat 1: missysbuddy ( $339.29 )
dutchboy2333 posts small blind [$2].
spector2 posts big blind [$4].

** Dealing down cards **

Dealt to HERO [ 5h 5c ]
HERO raises [$14].
Freewheelinn folds.
missysbuddy folds.
dutchboy2333 calls [$12].
spector2 folds.

** Dealing Flop ** [ 3d, 8h, 4c ]

dutchboy2333 checks.
HERO bets [$22].
dutchboy2333 calls [$22].

** Dealing Turn ** [ Qs ]

dutchboy2333 checks.
HERO checks.

** Dealing River ** [ 5d ]

dutchboy2333 bets [$60].
HERO raises [$177].
dutchboy2333 raises [$434].
HERO calls [$317].
dutchboy2333 shows [ 7s, Kc ] high card king.
HERO shows [ 5h, 5c ] three of a kind, fives.
HERO wins $1062 from the main pot with three of a kind, fives.