A particle accelerating through a viscous fluid carries a memory of its entire history via the Basset force: F_B = −6πa²√(πρμ) ∫₀ᵗ (du/dτ)/√(t−τ) dτ. This fractional derivative (convolution with t^{−1/2}) causes algebraic t^{−3/2} velocity decay — slower than exponential Stokes drag.