Long hair, plaited up, no hat, but goggles. I swim 1000m (40 lengths of a 25m pool) in half an hour. I did my first 2000m swim in years a fortnight back - the first week we weren't limited to 45minute sessions. Was tired after!
I don't remember my first swimming lessons, though I remember early lessons. I grew up swimming a lot - Mum worked at the pool, so most of the school hols were spent there, and in later teenage years, on my own account as lifeguard and swimming teacher. Came as a bit of a shock when I had to start paying for swims... I grew up not far from the sea, so often swam in the sea after school/work, and still do when I can.
I swim different strokes to break it up and make counting easier, and to focus on different areas. (Need to focus more leg work.)
Lots of people start swimming as adults - you might be able to find classes to improve your stroke, if that interests you.
Most pools will have lane markers for fast, medium and slow swimmers (and direction) do you go at a pace which suits you. I sometimes change lanes depending on whether I'm doing breaststroke or crawl. Sometimes on a Friday, when it's quieter, I get a lane to myself, bit other times are usually busier.
Another thing I do is aquafit/aquarobics, which is also low impact, and can be good fun. It's usually quite mixed ability - some can't swim well at all - and it's quite easy to adjust your pace to what suits you. Quite a few people will be there because they can't do high impact exercise, and the water supports your joints better.