ive been on my own a couple times, went on my own for my first trip. ended up having a year out there on me own 2010.
aslong as you are responsible you will be fine.
its all the idiotic plebs that end up in bother.
the thai people are fantastic, Thailand is known as the land of smiles for a reason.
its a great place to go too. I find Bangkok VERY busy tho. maybe a little too much at times. I tend to stay there for a night or 2 after arriving and then move on.
koh samui is a much quieter than Bangkok.. still lots to do and plenty of people about but nothing like Bangkok.
Pattaya is always fairly busy and you get a bit of everything there. there are around 10,000 bars in Pattaya and there is a great mix of people from all around the world. its an interesting place to say the least!
Phuket is much more for the couples I would say, a lot more chilled out than pattaya and Bangkok. Phuket is also full of Aussies as they can fly directly in.
theres a very quick account of how I find Thailand anyways..
Never liked Bangkok myself, a typical capital city. (Poluted, traffic bumper to bumper etc). One night at most if you want to go there, ko san road is not a bad place.
Been to Samui a few times, Chaweng is abit mental but if you are after the nightlife then thats the part of the island to go. If you want a more relaxing holiday then there are plenty of other parts of Samui more suited, it is a fairly big place so it caters for every need. It is by far the most westernised island in Thailand though so if you are after a more authentic Thai holiday try somewhere like Koh Tao.
Because of the backpacker murders in 2014 Koh Tao has somewhat of a bad name but whenever ive been I cant fault the place. Laid back, mostly full of divers so not as many idiots about intent on getting pissed into oblivion. Plenty of nice places to eat and great scenery.
Also been to Phi Phi, again great scenery but chaotic. its now the go to island on backpacker trails so its always chocker which somewhat takes away from the beauty of the place. It's more like a 18-30 holiday resort now.