It's rare to have cousins in the same age bracket as you are. Hence, when you do get lucky to have them so, cherish them with all your heart. This, I learned as I grew up with a stream of cousins. The sister and I gravitated, as a natural recourse, to the ones who were closer to our ages. Till date, my fond memories of my childhood are of those unlimited chatter sessions about sundry things that appealed to us at different ages and stages, of the to-and-fro camping in each other's houses during holidays, and of the excitement and anticipation of meetings after a period of lull. Indeed, cousins are truly a treasured species of human relationships.
Ever wondered why cousins fare better than your immediate sibling?
You get the best of both the worlds with cousins. When you're together, there's fun guaranteed. And, when you tire of each other, you can go back to your own houses! You're willing to share and quell the feelings of envy or anger because somewhere you know that these emotions are transient; lasting for only as long as the meet itself. The compromises and adjustments are not permanent; you can have your favourite toy or dress back the minute the cousin(s) leave. There's never the "you always favour him/her" thrown at your own parent. You can simply walk up to the other parent, the aunt or the uncle, and viola, the verdict will most certainly be drawn in your favour! You even get pampered by the cousins' parents. The sibling rivalry gets a breather till you meet next time, so you willingly extend the otherwise rare courtesy and don't mind donning the mantle of magnanimity.
When I see R and S together, it fills me with joy and satisfaction that they would know what it is to grow up with siblings even if they don't have each other's company every waking minute. Fights are rare and few between them. It's another thing that they complement each other very well and can almost read each other's minds when it comes to most things. S, for me, is like a daughter from another mother's womb. And, so is R for my sister. It feels great to have the kids grow up together even if we cannot always stay close by.
I guess it works for the parents too to have cousins as playmates for their kids. They're connected by blood yet not entirely your responsibility too. If a few caveats are met, then quite a win-win, I'd say.