Contemporary English Version (CEV)
Know how they're always trying to get you to sign up for a credit card at Target? They ask you this whether you spend $5 or $500, hoping that the allure of a discount will get you to sign up for something, even if you're not ready to. Often we sign up for things without considering the full implications of our decisions.
Here, Jesus is spelling out the implications of the disciples' decision to follow him. It's not just a one-time decision, it's a new way of life, highlighted by selfless service. They can't flip it on and off like a switch -- it's a serious decision with repercussions that carry over into every single way of life. It's a permanent decision to assume the role of servant, trusting that this leads into the way of eternal life. We are practicing now for the life that is to come.