I've done a lot of stupid, ISTP-type things in my time.
I did made the conscious decision to never do anything stupid while drunk, high or tripping since it would most likely be a bad decision. If I decide to do something while entirely sober, it's because I'm sure that it's relatively safe and won't result consequences that I'll end up regretting later.
In spite of that, I've lit myself on fire, flipped off balconies and taunted police just for the thrill of it and ensuing hilarity/hysteria.
I definitely identify with a lot of aspects of being ISTP that even contradict those of INTP - I can identify with both. Defined by my love for thrill-seeking, I would be ISTP. Defined by my preferences and my thinking, INTP.
Overall I would say I approach everything with an INTP mind, but I consciously allow myself to take in the outside world and just live in the moment. I am still primarily inside my own head, but I try to shut down my Ne and let Se have some fun for a while. I can't do it all the time, but I think that we all need to do a few things that are out of character if we want to truly be happy.
EDIT: I think I kind of derailed the thread, considering ISTP is not THAT far from INTP and it was meant to be about acting like nothing CLOSE to your type.
Sorry!
