Preschool was totally fun for her, so I could understand her disappointment at leaving. But she would tantrum when it was time to leave some other places that didn't always make sense. I remember when we took her to a see the school district psychologist to have her assessed for special education services. The psychologist didn't see anything "off" with my daughter during the assessment. She was about to disqualify my daughter from receiving services. Luckily, I was able to convince her to do a school observation so she could see how my daughter (didn't) interact with her peers. The psychologist was still doubtful that anything was up with my daughter, even when she started tantrumming because she did not want to leave the assessment. For whatever reason, staying and getting assessed was more appealing to my daughter than going to her swim class (which she loved).
Another "funny" place where my daughter didn't want to leave was Trader Joe's. She would carry on when I was done with my shopping and wanted to put my groceries in the car. I've heard many parents with children on the spectrum complain about how their children will tantrum because of the sensory issues--lights, crowds, and overwhelming experience. In fact, for many parents with kids on the spectrum, grocery stores are huge breeding grounds for tantrums. My daughter could handle all that. She just had too much fun at the market, particularly Trader Joe's, that she just didn't want to leave. Ever.
She still has transition issues, but thank goodness, nowhere like they were in the past! Now we can shop at Trader Joe's and leave with our heads held high and big smiles on our faces! Yay!