Hello,
I found it a little tricky to get your exact issue replicated as I dont work with rasters, but based on other similar things I have done I would try:
library(sp)
library(raster)
library(rgdal)
rastlist <- list.files(path = "D:\Learn\R\Clip\rasters", pattern='.tif', full.names=TRUE, recursive = FALSE)
rastlist_list <- as.list(rastlist)
allrasters1 <- lapply(rastlist_list, raster)
Your initial rastlist doesn't return a list, but a character, and this is where your issue lies.
I hope this works for you
edit
Thought the above fix was odd and realized the above wasn't the issue.
In your code, change full.names=FALSE to full.names=TRUE.
if you look at your rastlist with the setting to false, you will see you dont get the file path. As you are not setting your working dir, R will not know where to look for the files. By setting to TRUE you get the full file path so R knows where to go to get the file.