Quads FTW!!!

The case against limping AA or other premium pairs. It's too easy to not know where you are in the hand... Had he raised, PF, I would have been off the hand fast. BTW, villain is a semi-solid player; ultra tight (over 40 hands, he's a 5/2.5) In fact, I've seen him show down 3 hands total, 2 of which were in the blinds, and showed down very strong (he got 2-paired over 2-paired in a blind, and the hand below) and won with JJ. However, if you limp a good pair, be able to get away from it:

Poker Stars $0.10/$0.25 Pot Limit Hold'em - 7 players - http://www.thehandconverter.com/hands/441660
The Official DeucesCracked.com Hand History Converter

SB: $24.90
Hero (BB): $49.00
UTG: $13.40
UTG+1: $25.00
MP: $30.25
CO: $41.35
BTN: $4.55

Pre Flop: ($0.35) Hero is BB with 5s 8h
5 folds, SB calls $0.15, Hero checks
Crap beer hand...

Flop: ($0.50) 5h 5c 4s (2 players)
SB checks, Hero checks
- Nice flop. Hopefully, the SB catches up.

Turn: ($0.50) 6s (2 players)
SB bets $0.50, Hero calls $0.50
- And we have a nibble. I am not going to raise because I will fold out any bluff in his range.

River: ($1.50) 5d (2 players)
SB bets $1.45, Hero raises to $4.25, SB raises to $10, Hero raises to $31.45, SB calls $14.15 all in
- Hmmm... Quick check for a straight flush - no possibility. Does he have a straight? With a straight, are you stacking off here? It is too easy to be beaten by a boat. The only likely conclusion I can draw is a set of 4's bettered by running 5's full or 6's full. Needless to say, I am surprised:

Final Pot: $49.80
SB shows Ac Ad (a full house, Fives full of Aces)
Hero shows 5s 8h (four of a kind, Fives)
Hero wins $47.35
(Rake: $2.45)
If I'm him, I just have to consider the possibility that my opponent is stronger than me. The way I've played this hand is not exactly tricky. I carried him along the whole way, completely passively. I think he could have saved himself quite a headache by calling the raise. Obviously, he's not maximizing his return overall, but there is any infinite combination of hands that I can be checking a BB with. Besides that, I am flatting his lead on the turn. I have to think that I am raising his lead on the turn if I have 6's (i.e. two pair) or 4's. If I have 4's, am I raising / shoving his lead / 3bet on the river? Again, I was very surprised that he limped AA in the SB, but different strokes...