Gaining insight in anything from smoking cannabis? Dude, you won't care about insights when smoking cannabis. It numbs you and has a sedative effect on your mind.
There are two types of drugs. And not one type to gain insight and one type to get intoxicated. But instead there's one type of drug that sedates you and one type of drug that stimulates you.
Cannabis is a sedative drug. Not a stimulative drug.
Caffeine is a stimulative drug amongst others. If you want to gain a better insight, then drink a lot of black coffee. If you want to relax and don't care about anything, then use a sedative drug like alcohol or cannabis.
Drug induced Trance? A myth. It's like sleeping with your eyes open. You won't get any further in your life with them.
I generally don't do drugs anymore, because I am in love with my normal state of mind. If I feel a bit weary I down a Red Bull or two though. So I'm not entirely drugless.
I did cannabis, lsd, speed, cocaine, paddo's (shrooms), and ofcourse all conventional drugs like nicotine, caffeine, alcohol, etc. I did all this mainly to forget my worries, try out stuff, see what happens, being a teenaging rebel, etc. I'm not proud of any of it in hindsight. Because in the end, no drug can help me any better then being sober. No drug can solve any of my problems or make me feel better about myself in any way, living under constant influence is not living at all in my opinion. And in no way did I ever had an opiphany while under the influence of drugs that actually had any merit.
The only things drugs have done, is shift my worries and problems ahead of me, piling them up in a big pile of worry-goo.
I still do mild stimulants whenever tiredness is setting in though, but you still have to be careful with that. Can't trade off sleep entirely. :P (red bull, coffee, caffeine.)