Am I crazy calling with A high?

[AmonRaa]

NL50 Prima FR
Villain is 55/20. He's agressive and is continually making big bets. He's on a rollercoaster - he shows 7 high when looked up or close to nuts.

History with him:
AKs in MP raise 3$ after 2 limpers and he reraises to 12$. I didnt want to play OOP and havent seen him reraise before so I folded.

Get AA. Raise to 2.5$ after a limper, he makes it 10$ and we get it in pf. He didnt have kings cause K flopped, prima doesnt show mucked hands. I take it down.

To the hand in question. AK in MP 4BB raise, he calls. Flop JT7 rainbow. He has 70% fold to flop bet but I didnt want to bet here. He would call with a draw and him having position is bad. I check, he checks. Turn is a 3. I check with intention of calling - he may have anything, and he bets 5$. I call. River is 3. I check again. He thinks for some time and bets 12$.
My thinking was this. If he had any piece of the board on the flop he wouldnt slowplay it. Also if he had some kind of pp, he would bet it on flop, failing that he prolly wouldnt bet river again with it since he would be afraid I actually caught sth on the flop. I believed he is full of it and I called.