Knowing Your Child's "Limits"

We recently took a trip to visit friends and family. Traveling in a car, train or plane for long lengths of time, visiting unfamiliar places and restaurants can be challenging for any small child, but it is sometimes extra hard when you have a child with special needs.  Kids and especially those with Autism like their routines.  Dominic has been really good lately when we have taken him out to restaurants, we are basically able to stay as long as we want and chat amongst ourselves, while he entertains himself.  Well, on my birthday we tried taking him to my favorite restaurant, a Chinese place that I grew up going to.  The minute Dominic got to the restaurant, we tried to get him to sit in the chair next to me, that lasted just a brief amount of time.  He then went over to sit next to my brother, which would have been fine, but he kept lying down on the seat and trying to go under the table.  I decided I needed to sit over on the other side of the table with Dominic and he was able to be more focused.  All was well, until a giant fly went zooming past him. That was the straw that broke the camel's back!  Dominic jumped up from the table and started walking out towards the front door.  I gently told him we needed to get back to the table, so I could finish eating.  The more I pushed him, the more he resisted.  If you told a typically developing child to get back to the table, they would probably squawk a little, but would eventually go back and finish eating.  With Dominic, he still struggles with the "why" questions.  I asked him a few times "why" he didn't want to go back to the table, but I already kind of knew why.  He is terrified of bugs.  He sees one or hears one and it really flips him out.  He has a genuine fear of them.  It hasn't always been like that, so I'm still trying to figure it out.  Since there were a few chairs near the front door and a large fish tank, I decided to just sit there with him until everyone else finished eating.  Dominic calmed down some and kept asking to sit in the car.  I told him the car was hot and we were going to have to wait.  He didn't like it, but he waited relatively patiently.  It bummed me out about 5% that I couldn't finish my birthday dinner, but I also understood that we had probably pushed Dominic to his "limit."  What fun would it have been for me to take him back to the table?  He would have been really upset.  After a while, everyone else finished and we all left the restaurant. Haven't we all seen kids crying or upset at the store or at a restaurant and wondered what was going on?  Most likely, a kid had been pushed and gone beyond their "limits."  Don't we as adults get a bit cranky if we are pushed past ours?  It was fine that I couldn't finish my dinner the night of my birthday.  It made super delicious leftovers the next day!!!!!!!!!!!!!!!