I recently arranged various "shtik" items (eg arches, fans, balloons etc) for my friend’s wedding. I bought some flags too and when I tried to collect them back after the end of the dance, one lady who was dancing was reluctant to hand it back. I thought it would help her to dance more easily so I kept trying to take it from her. She was manifestly very annoyed at my persistence - probably viewing me as being pedantic about a flag, disturbing her dance and mingy at not letting her keep it. I will never see her again as she was not someone I knew. I don’t even know her name. If I can never obtain her mechila, how can I face Hashem on Yom Kippur or if she has forgotten about it by then, is that considered less iniquitous?
Shalom, Thank you for your question. You are correct that in such a situation a person should do tshuvah, which includes not only regret, determination not to act that way again, but also to beg forgiveness from the insulted party. It sounds like you have succeeded in the first two steps (and I assume you have or will perform "vidui" by turning to the L-rd in prayer and requesting His forgiveness also – as we do daily in the Amidah by saying "Selach La'nu"). However you are unable to request forgiveness from the lady in question as you don't know who she is. This means that you are what is called "anoos" – in a situation where it is beyond your control to fulfill a mitzvah. In such a situation you try your hardest to make amends – perhaps by being extra careful in the future in such situations – and leave the rest up to Hashem. I will add that it sounds from your question that you did not act out of any malicious intent at all, but there was merely a misunderstanding. If so, whilst it is unfortunate that it occurred, it is not so clear to me that you need to feel as badly as you do. As a person moves through this world they learn (hopefully) how to act with more and more tact, and thereby grow into nicer people. I bless you that you should be able to actualize your clear desire to bring light and love into the world. Blessings.