This one makes my blood boil. You're so guilty of this you should be locked in the supply closet and forced to eat the cafeteria special you can't quite make out.
Why is it so hard for you to get back to people promptly, respond to their phone calls, emails, and requests? Don't you want that from them? It doesn't have to be instant, just reasonably quick; use your judgment. But stop ignoring, forgetting, being distracted or just plain rude.
I know you're busy. If you weren't, I'd question why you were being paid. I know you're valuable. If you weren't, I'd wonder how you were still there.
But so are your coworkers, suppliers, clients—the whole world is busy and important. If you leave things untied, unfinished, or unattended at the speed of business today, you slow your company down. Not good.
If you only have the guts to change a few things about yourself, consider this one among them. You may find this resolution easier to carry out than you think.
Your company needs you to work hard, smart, clean, and fast. If you can't keep the wheels turning at maximum speed, at least keep them turning.
Contact Ken at firstname.lastname@example.org