Need to make a good impression with a vet Im shadowing?

I need to make a good impression on a vet Im shadowing. I followed him around for four hours and at first he was really friendly and willing to answer questions and even let me help but towards the end I think he was tired of me following him. Also, there were a lot of awkward silences, and I couldn't always think of questions to ask. When I left and said goodbye to everyone he barely looked at me. I dont know what to do. I feel as though I was attentive and respectful and I dont know what else to do. Im freaking out! I really need a good recommendation. Please help!