Second nature

A: I had to learn how to use a computer and a smartphone, because when I was a child, they didn’t exist.

B: I feel the same. However, for my son’s generation, using technology like this will be second nature. These kids have grown up with it.

Note: It refers to an intuitive, instinctive, or innate ability, habit, or trait usually achieved because one performs or practices a certain action very often or for a very long time. This expression is a shortened form of an ancient proverb, “custom is a second nature,” first recorded in 1390. It alludes to the fact that very frequently repeating something makes it seem completely natural or inborn.