library(ISLR)
library(mgcv)
library(gam)

# I get an error message when it runs this
gam.m3 <- gam::gam(wage~s(year,4)+s(age,5)+education,data=Wage)

# No error message when I detach mgcv
detach(package:mgcv)
gam.m3 <- gam::gam(wage~s(year,4)+s(age,5)+education,data=Wage)