State Pension Full Years requirement and anomaly on history

9MaineCoons

Hi All
I am extremely naive on the subject of pensions in any way shape or form and the recent discussions around topping up non full years to qualify for full state pension got me to check.  I cannot top anything up as last non full year is prior to 2006.
However, I have a query regarding my history showing on the Government Gateway.
First of all I am British, was born here but brough up in South Africa.  I visited briefly in 1988 as a 16yr old on 4 weeks holiday.  I then visited again for a year, doing some temping work, in around 1992ish before going back to South Africa.
I then moved permanently back to the UK in March 1999.
It shows from 1999 to current that I have all but one Full Year contribution (2002-2003) as not full. So currently I have (am in) my 25th current qualifying full year since 1999.  
Bear with me here.......
I have a further mix of 4 Full Years and numerous not full years showing from 1989-1999.
My forecast indicates I only have to complete a further 4 years of full years to qualify for the maximum payment of state pension when I am due it in June 2040 (so still a ways to go.... :-( )
HOWEVER, apart from a year in around 1992 in that period 1989-1999 I was not even living or working in the UK??????
Please could someone advise what I should do? Is this correct? If not correct do I have to tell them? Is it not their responsibility? etc etc.
Thank you all for reading this far and hopefully someone with knowledge and expertise can assist.
Have a great day.

molerat

Hard to pick out your exact history but I suspect 3 of those years are the tax years in which your 16th, 17th and 18th birthdays fell and you received the freebies.