To your distress, you discover that you agreed to attend your friend Sarah's 50th birthday party on the same night you're supposed to be at a convention in Las Vegas. Now, how did that happen? If I had to guess, I'd say that you said yes to Sarah's birthday (“Of course, I wouldn't miss it!”) when you were nowhere near your calendar. If you want to eliminate Colliding-Planets Syndrome, that calendar must be your new best friend.
Don't get cocky and put off entering a date, even if it's just for coffee the following day. Mark A. McDaniel, PhD, a professor of psychology at Washington University in St. Louis and an expert in human learning and memory, found that in the face of even a brief delay, older adults have much more difficulty than younger ones keeping in mind a task to be accomplished in the future. Refuse to agree to anything, ever, without a calendar in front of you. And don't write down cryptic things like “Starbucks,” because you'll draw a blank on which café you meant, and sit for a long time in the wrong one. Where you write things down matters: Multiple calendars—home, work, school—can only lead to trouble.
But what about things you must remember to do in the short term, like returning the nurse-practitioner's call in 15 minutes or putting money in the parking meter in a half hour? These are what Daniel Schacter calls time-based commitments, and putting them on your calendar isn't likely to help unless you habitually check it every five minutes. On less than an hour's notice, my most responsible friend, Jane, agreed to pick up her neighbor's son at school when she collected her own brood. Knowing she had to make it to soccer and ballet in Los Angeles traffic, she was the first in the carpool line, where she efficiently loaded her kids and took off. The neighbor's child sat waiting on a bench until teachers phoned his mother, who had nothing nice to say when she got in touch with Jane.
In midlife we have trouble remembering to do things at specific times because we're at the mercy of a million environmental distractions. One of Denise Park's studies demonstrated that elderly subjects were more likely to remember to take their medication on schedule than middle-aged subjects, because in midlife the crush of extenuating circumstances often got in the way. To remember to make that call to the nurse practitioner, Schacter told me, you're going to need an unmistakable cue, one that will be both available and informative. An alarm clock on the desk in front of you can do the job, but under no circumstances should you permit yourself to switch off the clock and finish just one more thing before you pick up the phone. And don't count on your PDA: You've heard those bleeps and blurps so often, you've learned to ignore them.