All in when the flop came down for me... you were the first to act.

Your raise was small enough to call/re-rasie and once that was done the money in the pot was worth calling your all in.

In the end you were outdrawn, you may have been able to scare the others off with an all-in you may not.

Boba

Some people have touched on this here.. and I think now you have the hindsight of what your opponent had its just eating at you. Let it go, regret is just a bag of bricks that weighs you down!

I personally would have opened much stronger on AK than you seem to have done, just calling would not have sat well with me.

Your opponent never had to make any decision in this hand, it was always played on his terms.

Just my 2 cents