Whenever I've bought fish I always went right home. When I've floated them, I always have the hood open and remember when I see them. Other times I've set a timer to remind me. Now, I drip acclimate all fish w/ an air stone in the bucket.
Some guppies are tough as nails. My father quit using a tank for 5 months and "took out" all the fish, but missed 2 guppies. When he got the tank ready to go again he saw the fish and was very confused to say the least