you would use complex and imaginary numbers in your daily life if you become a mathematician, electrical engineer, quantam mechanic, etc. otherwise, you would not use use them at all except in algebra 2, pre-calc, calculus....i hope that helped a little bit.
An example: A force of 10 in the x direction and a force of 5 in the y direction willproduce what total force and at what angle? Force = x+iy = 10+5i. The total force will be (10^2+5^2)^.5 or (125)^.5 or ~ 11.18. The angle will be atan y/x or atan 5/10 or .464 or 26.56 degrees.