150 hours over how long time? Those who aren't "naturals" may need more than that to "get it" and start seeing benefits (coming from someone who after several attempts in various forms finally "broke through", in lack of better words, on day ~6 of a 10 day Goenka-Vipassana retreat. That'd be ~10 h / day during that time).

After that I was able to do 30-60 minute sittings at home and experience the associated change. If you're also a very cerebral person you may also need a similarly concentrated "boot camp" or similar to get to some base level.

In a similar vein, if someone has extremely weak physique, it's not really convincing when they claim that physical exercise doesn't work for them, as they did spend 150h at the gym machines ;)