Could I have a brain tumor?

Yesterday, I was thinking back about some memories I had of my childhood and I remembered something that happened when I was about 6-7 years old. My whole family was at the Toledo zoo, grandma, mother, sister, brother. While we were there, I had a brief moment (about 5-10 minutes) where I had completely forgotten who I was at the zoo with. I had just wandered off from my family, forgetting who they were pretty much, and walked over to a different family who was laughing really hard about something. I just walked up right to them and started listening to their conversation amd nodding my head at the guy who was talking about something ( I forget what exactly ), trying to encourage him to continue talking. I forgot completely about my own family at that point, as far as I was concerned, this WAS my family. Then, my grandma had called my name, it took me a second to register that that was indeed my name, and I remember feeling very confused, not sure why I had gone over to those people. I did remember walking over to them very clearly, just not why I did it. Some other things have continued into my adulthood. Just some examples are, I frequently accidentaly type words completely backwards, it's common for me to mix up my words, saying something like 'the mact of the fatter' (I believe that's a spoonerism?) and won't realize it till someone points it out, my short term memory tends to be garbage half of the time ( though my long term is pretty decent ), whenever I'm thinking about a conversation I had in the past, I often will answer question I was asked in the memory out loud, even if it's an entire sentence, startling myself and causing others around me to give me wierd looks. I've never needed any special education though, just the opposite actually. Straight A's throughout school, part of the gifted student programs in middle school and primary. I just wanted an opinion really, yahoo answers usually provides some interesting insight. Would it be a good idea to go see a doctor, just to see what he or she thinks if nothing else?