It seems to me that there masy be interesting subtleties between
1) I forgot to ask you.
2) I have forgotten to ask you.
Does the second one mean that I have kept forgetting to ask you about something lately?
Just a few random quotes:
1) If you have forgotten to ask some pertinent information during the interview, there is no need to panic.
2) It is just because people have forgotten to ask themselves this question that Shakyamuni Buddha came into this world to urge us to investigate the problem of birth and death.
3) I have forgotten to ask for permission before I took actions and I have forgotten the glory of my youth when I never questioned the plan you have for me.
Do you find them odd?