Advice: little guy hates coming, but has fun while here!?

I had my kids in daycare for a few months while I worked outside the home, my son who at the time was 4, would whine every day that he didnt want to go, and it was a battle. One day he threw the biggest fit in the front foyer of our daycare provider's home, she just said for me to leave, and call her later on to see how he was. She said the second I closed the door behind me, he looked up at the door, looked up at her, picked himself up and went downstairs to play with the other kids and had a great time all day. And when I went to pick him up, he was dissappointed that I was early!
I had 2 girls who were like that with me, big, dramatic drop off almost every morning, fine all day and never wanting to leave at night. I just made sure to share that with their mom and also tell her of my experiance as a daycare parent!

I have a little boy who's been with me since 13 months, now 20. He's started throwing a huge tantrum when Mum drops him off, once last week & 2 days so far this week. He holds on to his things (lunch bag or hat & coat) and will cry and cry and not want to leave her until I tell her to just leave and I try and carry him so he can't run out or grab her legs! He's a big toddler & I'm a little person :) so when I try carrying him in that state he almost pulls me all over the place...that's not the problem though. Then when mum leaves I put him back down and let him cry it out for about 10 mins, I take his things from him telling him 'it's time for breakfast' and/or 'lets put your things away and we'll get them out when it's time to go outside again'. At this point he's livid because I took the things from him, not before I first gave him a few chance to 'put them where thy belong'...Anyway today after doing that, I put him in his chair for breakfast, cried a little and then sat happily & ate...playing happily right now too! I have noticed him trying to test my patience a lot in the past few weeks, won't listen when I ask him to do something, pretend he can't hear me etc...terrible twos? Then I give him 3 chances to listen and put him in time away if he doesn't. I'm wondering if taking a dislike to me because of this? He's my only all day dck and I really like him & his family and don't want be a negative impact.
Any help/advise would be appreciated.
Thanks
AO
Sorry this is so long!

Every few months kids go through another round of making sense of their world given their new level of understanding and this is often an age when they do it - somewhere between 18-24 months. They now understand the concept of mine and yours even if they do have a preference for mine but they understand it as you can't have my things. So he holds onto what is his. It is also his lifeline to home and he also is old enough to comprehend the mom goes and he is sad about that. As mean as it sounds I have found I do much like you are doing and maintain the security of daycare be letting child know the rules did not change - we come in, mom goes, things go in cubby, we play. Be as consistent as possible and keep your explanations brief. This is not the time to go into long lengthy explanations about it all. I know some say to talk about their feelings etc. but I find they don't grasp what a feeling is because it is abstract. They see feelings in terms of personal effects going away, the order of the day mixed up, etc. So just keep what you are doing and it too should pass like all phases of childhood. I do try to go easy on the timeouts or whatever recognizing that the behaviour is normal and not intentionally bad but stick with the firm reminders and physically make things happen like taking and putting away things, or moving child to another area of the room to sulk or whatever. I have all toddlers so on any given week I have someone in the throws of not a good week.

It seems to be just the age (sorry) babies grow into toddlers and toddlers into preschool kids and when they hit those transitions they have to reexamine the world order (so to speak). Kids need to make sure that you are still going to be there for them that they will still be loved, and that limits are intact, despite the changes.