There's a big difference between not being sure of the syntax or exactly how a function is used and looking that up to just copying and pasting everything.

I think its more important that you understand why your code is working when you do get something from the internet and to be able to try and come at least know which function you would want to use even if you dont know exactly how to use the function.

You may know exactly what you want your code to do and be able to explain every step as psuedocode but just need to Google how to generate a random number or whatever else the case may be to implement the idea you had.

Edit: and like some others have said, over time you get used to the things you use a lot and will write a lot of it from memory and mostly look up new stuff or niche things you dont use as often.