Lesson one: Do not feel bad if you end up spending most of the time in your room!
When our first born made his appearance we didn't change our way of living (or travelling) much. He was carried around wherever we went and seemed happy enough with sleeping wherever he happened to end up. We even dragged him on a 5 weeks trip to Asia when he was a mere 6 weeks. In hindsight I must admit that I wouldn't recommend that to anyone else.
Anyway, travelling with one baby is a breeze. However, travelling with two is a completely different bag of fun. I soon had to realise that all my expectations of days in the sun filled with fun and soul developing activities had to go. Really really go. We would be lucky if we even made it out of our room for two meals a day. No, not that bad, but we would definitely spend more time in our ac-room than we had done on previous trips to hot and sunny places.
After having walked from the hotel to the beach side in 34 degrees and glaring sun, stopped at a cafe for some much needed cold refreshments, spent the best part of an hour taking tuk-tuks to no place in particular because the 4-year old can not think of anything more fun and exhilarating than driving a tuk-tuk, we finally made it to the beach. At which point every body besides the 4-year old were hot and sweaty and ready for a cold shower. But we managed to spend a good half an hour during which the 4-year old dug for crabs, went for a swim, and in general had a ball, we ate pineapple and bbq chicken with sticky rice, made friends with a group of locals having a picnic near by, the 5-month had been admired by everyone around, and managed to pee all over the sarongs. So then we went back to the hotell after having spent a whopping 4 hours out and about.
All in all a very good day.