Watch a sporting event from the 1980s, then watch one from today.
When watching American Football, I had to wait until the commercial break to find out the score, the quarter and the time remaining. It was rarely shown during the game. Now, constantly on the screen is a display of the score, time remaining, quarter, down and distance, other scores, player stats, etc.
Much like video games have all sorts of hearts, lives, scores or statistics all over the screen, I think our lives will have the same sorts of stuff, and we'll get used to it.
Streets we walk by will be labeled. Buildings will be labeled. People we walk by that we know be labeled with names. You won't forget anyone's name anymore. Well, you will, but you'll be reminded of it. When you walk by a building with an event going on, it will tell you - 'Free Museum entrance today', 'Buy one / get one on pizza purchases today', 'Birthday party starts here in 15 minutes'
We'll get the time and date, and weather, always displayed in the corners of our view. We'll be warned - 'it's going to rain in 2 minutes!'. 95% of our screen will be transparent to show the surrounding area, except when we go to watch a game or something.
It will be a different future, and your kids will come to expect it, and won't be able to live without a HUD constantly available to them in real life.