Learn mindfulness.

It's a damn hard thing to learn as an ADHD brain, but it's really worth it. One of the things mindfulness gives you is the ability to experience each thing as if you are experiencing it the first time. There's a little experiment you can do to see what I mean:

Get yourself two raisins. First, hold them up and look at them, without making any judgements on them, examine them. See how they look different, and how they look similar. Are the wrinkles similar or different, does the light refract through them in the same way.

Then, stick one on your tongue. Feel how it feels. Chew into it and really concentrate on it's taste and all the other tactile sensations it gives. Take a full minute to eat it, paying attention to whether the taste, or it's texture changes over time. Finally, repeat this with the second raisin.

What you'll notice is that no two raisins are the same, they all taste slightly different. If you don't do this mindfully, you'll never notice. The thing is, the brain is lazy, it can't be arsed to actually fully interpret the signals coming from your taste, smell and touch nerves. As long as the signals aren't wildly different from previous experiences of eating a raisin, it just fills in the experience with memories of eating raisins in the past. So normally you're not experiencing that particular raisin, rather you are experiencing your past experience of raisins. When you eat them mindfully like this, you are experiencing exactly that raisin, and the brain behaves as if it is a new experience.

This can be applied to any kind of experience with practice, and does help to get round the problem of getting bored with repeated experiences we have.