Thanks for all these comments - which provide experience and plenty of common sense. Whilst describing my feelings as claustrophobic is a bit strong, and in no way like the claustrophobia that some suffer, it helped to express the somewhat pressing urge (not panic) to remove neoprene. The practice that training includes donning and wearing of heavier suits is first class, and please include getting out of them. Instructors please note. Comment on neck seals was very informative.
Wearing the suit indoors, or even in the garden sounds funny but it is absolutely right. The first time I was due to go snorkelling I needed to get used to limited field of vision and breathing through the mouth - so wore mask and snorkel around the house doing everyday chores - result - snorkelling was an easy calm experience and led on to scuba diving. And I wear any new gear around the house, then in the pool before going away.
Somewhere on the Board there was a hilarious thread about problems people had getting into and out of vests and suits. Useful tips eg turning up a hem on a rash vest and filling it with water helping to peel it off. And a vision that haunts me is also on that thread about when pulling off a rash vest - a woman pulled a tight rash vest off over her head but became trapped by the neck seal and her bikini top also got pulled off by the vest. So she is trapped with her arms over her head, wrapped in the tight rash vest and bikini top on the floor, staggering around the dive boat asking for help.
I must find that old thread again.
