I just got back from a tourney that I usually win without any money . I am wondering if I played the last hand stupidly....

I had A J about 4 seats after the BB.

Blinds are 3/6 and I make it 12 to go.
2 Players in front of me and 1 player behind me call.

Flop comes 4-J-10
Check to me. I bet 18.
Player behind me calls, two players in front fold.
Turn comes Q.
I push all in. Player calls.
River comes a rag and player turns over Q 9....

I was wondering whether I should have played more aggressively on the turn.... The player is kind of stupid though. I bet he would have called on the straight draw.