Depends a lot on how they are taught.
For example, if I spend 10 mins teaching one, then go to another, then another then another, chances are they'll be forgot.
But if they lead into each other, so that in order to get to that 4th, you have to do the first 3, or at least attempt them, then people are more likely to remember all 4.
Or if there is a "review" that helps as well. Something like
Technique 1 for 10 mins
Technique 2 for 10 mins
Alternate Technique 1 & 2 for 5 mins
Technique 3 for 10 mins
Alternate Technique 1,2 & 3 for 10 mins
People will remember something a lot better if you do it, then do something else, then get them to do it again.
Another example would be a flow drill, I could teach:
guard pass -> Side
Side -> mount
Bridge & Roll -> Guard
to a brand new student, and they would have the general feel for each. Could probably even through in a sweep & elbow escape. There would be very little in terms of details retained, but the basic concept could be retained.
Or on the flipside, you could work something like keeping posture in guard... not really a technique, more of a concept. I could explain the concept to you in about 30 seconds and you'll remember it, but it's going to likely take many classes before its "there"