Yes, it is possible that you've gone your whole life without being diagnosed. My brother had more problems than me, and so he got more help and attention, while I, being somewhat able to muddle through, didn't get the attention with specialists because in general my grades were okay until a certain point though I never made the honor roll, I'm reasonably intelligent, and when I did run into serious problems, because I'd never had behavior problems, my parents thought I just needed to "buckle down and work harder".

There are a lot of tricks you can use to help deal with ADHD aside from, or in addition to, medication. One that I've used a lot lately and has helped tremendously is having task-specific 'stations' for things. My computer desk is my home management station, and I keep everything related to home management: books on housekeeping, cooking, ect; budget kit and calendar, all right here (and this also keeps me reminded of my purpose here, so I'm less likely to get sidetracked into a computer game). I have other stations for writing/homework; personal grooming, exercise, home improvement/design, and so on. Each one has a few decorative items that remind me of something specific to the task that station is for, a framed memorable picture, quote, or poem that inspires me; and everything needed to do a job (plenty of sharp pencils and pens that work at the homework station).

I can get into a 'zone' and bounce from station to station all through the house and at each station I can get on task. This also helps me organize, and my home stays fairly clean (cleaning/organization is generally an issue for people with ADHD though it is ESSENTIAL to be organized to manage it). I can do five projects at once (as long as they are in different ‘realms’) effectively because the materials for each project stay confined to a different area. Multitasking also keeps me from getting drained by staying on one task for too long.

Well, that got long, but I hope it helps some. Medication can be wonderful, but doesn’t always work out long-term (side effects got to be too much for me, and if you don’t have insurance cost is a serious concern). Good habits are essential to living with ADHD.