If you pretend or think something other than what is stated then you are being contradictory to the facts, you are delusional and mistaken. In this case, if you don't think that "T" is a real cost then you are being contradictory to facts that show that "T" is a real cost.

I have to start to make this clear that this is a humorous statement- it a joke meant to be a little funny. To pretend otherwise would be delusional is an open statement not directly addressed to anyone. That open statement is if you think the "T" (taxes) are not important than you would delusional (sometimes people incorrectly would say "crazy"). It's a joke because taxes are one of the most complained about things yet the most important of society. In this case they are saying that out of all the things to consider: the most money lost will be with taxes (real cost). To ignore(pretend) this would be like: to not have money but go to a restaurant and order food. You don't ignore taxes that's crazy (delusional).