Villain is 38/13. I have A8 in the bb and flop top pair on a dangerous board. Am I retarded to lay this down?

Full Tilt No-Limit Hold'em, $0.25 BB (9 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

saw flop | saw showdown

Hero (BB) ($24.55)
UTG ($69.22)
UTG+1 ($5)
MP1 ($50.32)
MP2 ($10.09)
MP3 ($5)
CO ($25.39)
Button ($17.65)
SB ($24.40)

Preflop: Hero is BB with 8, A
UTG calls $0.25, 5 folds, Button calls $0.25, SB calls $0.15, Hero checks

Flop: ($1) 6, 8, 5 (4 players)
SB checks, Hero bets $1, UTG calls $1, Button raises to $3, 1 fold, Hero folds, UTG calls $2

Turn: ($8) 4 (2 players)
UTG bets $3.50, Button calls $3.50

River: ($15) 8 (2 players)
UTG bets $4.50, 1 fold

Total pot: $15 | Rake: $0.75

Results below:
UTG didn't show
Outcome: UTG won $14.25