I read this line in Merriam Webster word of the day-fastidious
"I may have thrown in a little thing here or there, but I'm pretty fastidious about sticking to the script if I like it…."
— Michael Shannon, Screen International, 21 Nov. 2016
Can someone please tell me what that line meant in the context. I'd like to know only the meaning of I may have thrown in a little thing here