36 is overkill in the majority of cases unless you're building the wheels with very thin spokes or putting it on a tandem (my tandem has 40 spoke wheels).
For general riding a well built 24 or 28 is plenty strong. You have to watch it a bit more because if a spoke loses tension the wheel is more compromised than on a higher spoke wheel but that shouldn't happen with regular maintenance unless you do something like catch a branch in your wheel.
I'm 6'1" 220-230 lbs and my road bike has 20 spoke Mavic Aksiums. Those wheels are practically indestructible and I'm not gentle. I race cyclocross with an older set of tubular Ksyrium SSCs, 20/24 spoke. My fixed has 32 spoke Alex DUBs laced to Formulas because that's what it came with. I beat the snot out of them, no problems. No tricks either unless you count the occasional speed bump/pot hole bunny hopping.
I'm sure I would have had problems with my fixed wheels because out of the box the tensions were all wacky. I loosened all the spokes until the nipples showed thread then tightened them all uniformly until the wheel started to come up towards proper tension. Then I broke out the tension meter (bike co op) and brought the wheel up to a nice uniform tension. I barely had to true it once I finished. Now I have a wheel where forces are distributed uniformly around the rim.
If the wheel has even spoke tension it will be strong with 20, 24, 28, 32, or 36 spokes assuming it was built with good components by a good wheelbuilder who took the time to get the tensions even. A 36 spoke with wacky uneven tension will break and go out of true because the forces are being distributed unevenly.
My Mavic wheels were all fairly uniform tension when I got them, even my Ksyriums which had seen a lot of miles before I got them. The only thing I've had to do to them is adjust the dish over about 2mm on one set of Aksiums (I have two) so I could swap wheels without adjusting my brakes.