I would highly recommend you educate yourself about Islam....as “anyone” with even a rudimentary understanding of Islam understands there are numerous people who “convert” to Islam.
The operative word is "sane".
That and the threat of death has supplied the converts to Satan's plague called Islam.
Sanity has nothing to do with those who convert to Islam...though those who are are not exempt.
People ‘choose’...that’s the bottom line...the same as all other choices one makes in life. Sane and otherwise.