the context is way mixed up.
for example, if you toke up some weed, you feel it instantly. ---- INSTANT GRATIFICATION
or
if you drop acid you feel it within an hour more or less. ---- TOLERANCE MITIGATED PLANNED GRATIFICATION
but
if you meditate, you may or may not enter absorption if you concentrate well (1), and if you concentrate well and do not drift, you will attain some equanimity(2), and if you attain some equanimity, you may enter an enhanced state with jhana like experiences(3), and if you maintain the sustained concentration with equanimity you may enter a samadhi state(4). ---- NO GRATIFICATION FOR MOST WHO TRY
Usually you have to do it frequently and regularly to get (1) (maybe 65% of those who are interested), and if you do you may reach (2) (say 70 percent), and most that are persistent (~75 percent) do reach (3) and about 60 % of those who try actually get to (4), but this is not the purpose of absorptive meditation. So ~20 % of those who try get a good feel for what meditation can provide during the sitting.
1, 2, 3, and 4 are similar to what you may get on a good acid trip. jhana like experiences (3) include CEV, OEV etc.
Never the less, this is not the spiritual part of it, this is just the trappings, the visions mean nothing, the mandalas and visitations mean nothing, the feelings of timelessness and oneness mean nothing, they are distractions although they are very invigorating and charming.
This is where most aspirants fuck up miserably, often feeling like they are jesus re-incarnated or the next buddha or messiah.
the numbers are telling, maybe 1 in 5 people try and 1 in 5 of those get some samadhi that is one person in 100 who have any sense of what I mean, and of them more than half at least for some time think they are the cat's ass spiritually speaking, put here on earth to save the masses.
but like I said this is spiritual crap,
the real work is the practice, which means regular application of awareness and sitting by one's self with one's self and not reacting to all the phenomena of daily life for a period of time.
this builds a few important spiritual abilities:
the ability to be unmoved by triggers
the ability to remain present when others run away
the intent to witness things full circle
confidence
calmness
These abilities are hugely important in helping yourself and others through mental, spiritual, emotional challenges.
They do not come from one attempt of sitting, and they do not automatically come from dropping acid either.