To assume something isn't true based solely on the fact that you've never experienced it demonstrates a profound lack of empathy and critical thought. So does taking the time to complain about trans people in a meme instead of having an actual conversation with another human being.
If you take the time to do the latter instead, you might develop a shred of empathy, but you're afraid to, because that might mean you have to admit that you're wrong.
Why would you tell that to them? Schadenfreude? It's just asshole behavior, and probably false even under your own definition (you should read up on medically defined biological sex, chromosomic vs genetic, gonadal vs apparent, also sex hormones and embryological development of primary sex characters), not to mention current definitions that are much more useful in practice. And even if you want to keep believing that trans people are just delusional and their ideas are completely false, think whether it would be fine for an atheist to laugh at someone whose only reason to keep going is God.