I ran this under 2.3 and was confused.

yourmom.rb

# frozen_string_literal: true

class YourMom
 	def speak
 	  msg = "You'll be late for school! It's #{Time.now}"
    puts msg
    puts "...object id was #{msg.object_id}"

    msg2 = "Eat your vegetables!"
    puts msg2
    puts "...object id was #{msg2.object_id}"
 	end
end


# Works. The interpolated strings aren't frozen, but the
# the "Eat your vegetables" is
mom = YourMom.new
mom.speak
sleep 2
mom.speak

puts " ~~~~~~~~~~~~~ "

# Doesn't work - string is interpolated, then frozen.
# Returns the same time + object_id the second time
msg = "Thanks for finally showing up to school. It's currently #{Time.now}"
puts msg
puts "...object id was #{msg.object_id}"
sleep 2
puts msg
puts "...object id was #{msg.object_id}"