I learned this trick, or something similar, I believe, from Adam Grant's book, "Give & Take."
As a Giver, it can be hard to do something for myself or tell people "no" . This can include asking for help, a raise, time off, telling someone I can't go to their event or don't want to buy their service or product. The "trick" is to look at who else benefits from you getting the thing or saying "no".
If I got a raise: Kindle could go to doggy daycare & live a happier life; I would be more focused at work & less worried about paying my bills or if I was being paid fairly.
If I got time off: my team got the opportunity to show everyone(& remind me) how fabulous they are & I got to decompress.
If I told someone I couldn't go to their event: the event would be filled with people who were really present & happy to be there; I got to do what I actually wanted or needed, and see them when I could be fully present with them.
The world gets better when you do what you know you want to do! You inspire those around you and set a great example for those coming up behind you. So, if there's something you want to do, but think it's selfish to do or take the risk, I encourage you to think about the example you'll be setting by moving towards it!