You can't go through life regretting decisions that were good at the time.
Not wanting to forget your vote (whether for Trump or HRC) is not necessarily a reaffirmation of the individual voted for...it could be just the reaffirmation that the vote was the best vote you could make at that point in time...not wanting to forget a vote may just be a reflection of a person's personal view that second guessing past decisions like that is not helpful. You can learn from such decisions without wanting to forget them.
For me, if I wanted to forget my vote, it would mean that I decided I made the wrong choice at that time. I don't think I did. So, I don't need to forget that vote. That doesn't mean I'm a big Trump supporter now, or I like everything he does. I don't. But, I still think I voted for the least awful person from my perspective. It was the best decision I could have made at that time, so I made it. No need to feel bad about it.
Now, having said all of that, if the Left predictions of Trump created concentrations camps were even remotely coming true, I might want to forget my vote. So, I guess there is a counterpoint. Thankfully, that was all insanity.