It's hard to keep the practice up for sure. It takes years of sustained practice to really feel the benefits, and then it's constant hard work (right effort) - I did do Zen classes for a while, the instructor said a good hour a day is what was necessary, every day, and if you're 'on the path' constant mindfulness of everything is also required - the meditation is just a supplement.
It's a very easy practice to quit!
I think there's still benefits and even if your mind is wandering during a session of whatever length, I feel that at least those thoughts have had a chance to get out, probably means you'll be calmer of mind during the rest of day.
Ultimately I think the best advice I read was Shunyru Suzuki - Zen Mind, Beginners Mind, chapter 1 - the purpose of sitting is just to sit, nothing more.
I agrer, the purpose of meditation is just to sit and never liked meditating on music or for a purpose. I started medtitation about a year before I started practice yoga and quit it at the same time I quit yoga. I still meditate once in a while but it's not the same anymore. It should be taught in schools in my opinion.
Yoga's a form of meditation if you ask me!
Ad long as it's meditation and not mindfulness. I can't stand the later taken out of it's broader context. It just winds me up - people 'acting' mindful rsther than being mindful if you get me gist.
People are acting in too many situatioans these days