What happens after joining up with my mare?

So my mare joined up with me today, is there anything I should be sure to do after? And will a horse ever fake a join up or is it real 100% of the time? I'm new to this whole join up thing and want as much info as possible. I know she really joined up with me because she walked right up to me and followed me like a dog.. but will she forget everything and revert back to before? Please don't be rude or give me dumb *** answers, I want the best for me and my mare, you should understand that!