People without college science and physics experience should struggle.
What BS!
For the record, my college science consisted of Geography (4 semester hours), Astronomy (3 semester hours), Biology (4 semester hours) and math theory (3 semester hours) -- all finished by my sophomore year, 1968! (And yes, I did have a year (?) of physics in high school -- 1965.)
I did my DM in 2007 so I think it is fair to say that my "science background" did NOTHING to help me.
I did not find the PADI DM science parts all that difficult. Hey, this is stuff that is really basic -- honest. Let's see, what ARE the issues?
a. Displacement -- OK, an object gets placed in water and it displaces "X" amount. "X" amount weighs "Y" since we know how much water weighs and it is simple math to multiply "X" times the amount water weighs (a factor that is given to you on the exam!). Since we also know how much the object weighs, it is a simple comparison -- does it weigh more than the amount it displaces or not?
b. Gas Expansion -- That you should have learned in OW (page 17 of Chapter One -- OW Manual). 33 FSW/10 m = 1 ATM/Bar. It is a very simple progression and one that should be known by anyone even remotely interested in diving -- 1 atm (surface) -- 100% of volume; 2 atm (33 FSW) -- 50%; 3 atm (66 FSW) 33%; and so on. Hey, "this ain't rocket surgery!"
Honestly, NONE of the Physics, Physiology, etc. is at a very high level and even a modicum of study should prepare someone who has basic diving knowledge and experience should find it easy.
No, you do NOT need college level science to learn the PADI science -- just the ability to do basic math and comprehend what you read.