Quote IslandGirl33: IMO, 2 years IS a long time and yes, feelings can and do change in that time. Especially since in his mind she was dead, not simply "not in his life".
Also, I sorta considered his trip to the lab a way of confirming that Robin was NOT alive more so than "oh my, I hope I find her there". Remember, he was basically being told that his mind is playing tricks on him. All that on top of all the different "normal" emotions one feels when they're getting married.
Actually 2 years is not that long. I was seperated from husband when he died suddenly and I was lost for more than 2 years. It was not until I was laid off from work and had 3 months before I found a new job that I really started to heal. At that time as I finally came out of my funk and when I realized I had actually been in one. I realized a lot of my choices were done out of desperation to feel normal and to hold it together for my children. When that song by Rob Thomas of Matchbox 20 came out...I'm not crazy I'm just a little unwell...right now....well that was me. I functioning and moving on with my life but I was not.
I know GH is not real but honestly, Patrick was deeply in love with his wife and child, his family and as wonderful Sabrina has been to Patrick and Emma he was not truly ready to be remarried, it was as if he was forcing himself to get married and move on because it would be best for everyone around him and at least Sabrina helped him function more than he was before. Clearly he was still not done greiving for Robin, that is why he had to watch the video of her telling him to move on because he couldn't do it on his own.
I like Sabrina and feel bad for her, but deep down Patrick never wanted to choose or move on, he never wanted his wife taken away, he just wanted his family intact. It will be hard to let Sabrina's friendship go but his love for Robin is stronger, he is just in shock about everything right now.