Young skin functions differently than mature skin in a number of ways such as:
Dermal-epidermal junctions are tighter
collagen production is higher
the immune system is more capable of removing non-viable skin cells. As we age, these non-viable cells begin to build up and signal other skin cells to enter this state of senescence as well (propagating the aging process)
If you're under 30, you don't have to worry about these things, so, we've pared down our choice of ingredients for this line, and the primary goal of each of these products is to prevent the signs of aging by protecting skin from the elements. This entire line is crafted with the intention of long term use.
And, remember, each of these products are multi-functional, so you CAN just choose one!