Interacting with celebrities has been a part of con culture from the beginning, and it can be hard asking a question of someone whose work you've admired for a long time. It can be cringeworthy going to a Q&A and hearing people fumble trying to formulate a variation on one of the five questions that the last twenty people before them have asked.
Just remember, these celebrities are regular people. They have their manservant put their solid gold trousers on them one leg at a time, just like everybody else.