One of the best things to come from the legalization of marijuana is that one can better control one's experience while under its influence. In the past, there was no way to be sure of the type of strand you were getting. Even if a dealer told you what type it was you just had to trust that they had accurate information and that there were trustworthy but some drug dealers are not trustworthy.
One time I ate a weed brownie that a friend had made. We did not discuss whether it was indica or sativa because this was before weed was legal and such a topic rarely came up. I knew from experience that edibles had a much stronger effect so I only ate about half the brownie. A few hours later I was high as a kite but I needed to go to bed. I lay in bed with my mind racing for a while and then I just had to get up and move around. I walked around my apartment going over everything I had ever contemplated in my mind. Where was I? Where had I been? What should I do with my life? And a thousand other questions raced across my mind as I paced around for hours.
Although this is an extreme case this kind of uplifting effect is typical of sativa strains of marijuana. Indica tends to have the opposite effect. Instead of acting like a stimulant indica acts like a relaxant. It slows you down and allows you to chill out.
Nowadays I only like to smoke at night when I am done doing anything particularly important. This means that I smoke later in the evening most of the time and if I were to smoke a sativa strain I would have a harder time sleeping and the effect of stimulating my mind along with decreased short-term memory means that my stream of consciousness becomes more chaotic as concepts are created and forgotten quickly. With indica, short-term memory loss still introduces a small amount of chaos but in a much calmer way.
Cannabis 101: What's the difference between Indica, Sativa & Hybrid?